Power-to-weight ratio

Power-to-weight ratio (or specific power or power-to-mass ratio) is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measurement of actual performance of any engine or power sources. It is also used as a measurement of performance of a vehicle as a whole, with the engine's power output being divided by the weight (or mass) of the vehicle, to give a metric that is independent of the vehicle's size. Power-to-weight is often quoted by manufacturers at the peak value, but the actual value may vary in use and variations will affect performance.

The inverse of power-to-weight, weight-to-power ratio (power loading) is a calculation commonly applied to aircraft, cars, and vehicles in general, to enable the comparison of one vehicle performance to another. Power-to-weight ratio is equal to powered acceleration multiplied by the velocity of any vehicle.

Contents

Power-to-weight (specific power)

The power-to-weight ratio (Specific Power) formula for an engine (power plant) is the power generated by the engine divided by weight of the engine as follows:

\begin{matrix} \mbox{P-to-W}&= P/W \\ \end{matrix}

A typical turbocharged V8 diesel engine might have an engine power of 330 horsepower (250 kW) and a weight of 835 pounds (379 kg),[1] giving it a power-to-weight ratio of 0.65 kW/kg (0.40 hp/lb).

Examples of high power-to-weight ratios can often be found in turbines. This is because of their ability to operate at very high speeds. For example, the Space Shuttle's main engines use turbopumps (machines consisting of a pump driven by a turbine engine) to feed the propellants (liquid oxygen and liquid hydrogen) into the engine's combustion chamber. The original liquid hydrogen turbopump is similar in size to an automobile engine (weighing approximately 775 pounds (352 kg)) and produces 72,000 hp (53.6 MW)[2] for a power-to-weight ratio of 153 kW/kg (93 hp/lb).

Physical interpretation

In classical mechanics, instantaneous power is the limiting value of the average rate of change of work done per unit time as the time interval Δt approaches zero.

P = \lim _{\Delta t\rightarrow 0} \tfrac{\Delta W(t)}{\Delta t} = \lim _{\Delta t\rightarrow 0} P_\mathrm{avg}\,

If the work to be done is rectilinear motion of a body with constant mass m\;, whose center of mass is to be accelerated along a straight line to a speed |\mathbf{v}(t)|\; and angle \phi\; with respect to the centre and radial of a gravitational field by an onboard powerplant, then the associated kinetic energy to be delivered to the body is equal to

E_K =\tfrac{1}{2} m|\mathbf{v}(t)|^2

where:

m\; is mass of the body
|\mathbf{v}(t)|\; is speed of the center of mass of the body, changing with time.

The instantaneous mechanical pushing/pulling power delivered to the body from the powerplant is then

P_K =\tfrac{1}{2} m 2|\mathbf{v}(t)| \lim _{\Delta t\rightarrow 0} \tfrac{\Delta |\mathbf{v}(t)|}{\Delta t} = m \mathbf{a}(t) \cdot \mathbf{v}(t) = \mathbf{F}(t) \cdot \mathbf{v}(t) = \mathbf{\tau}(t) \cdot \mathbf{\omega}(t)

where:

\mathbf{a}(t)\; is acceleration of the center of mass of the body, changing with time.
\mathbf{F}(t)\; is linear force - or thrust - applied upon the center of mass of the body, changing with time.
\mathbf{v}(t)\; is velocity of the center of mass of the body, changing with time.
\mathbf{\tau}(t)\; is torque applied upon the center of mass of the body, changing with time.
\mathbf{\omega}(t)\; is angular velocity of the center of mass of the body, changing with time.

Along an obstacle free positive inclined straight road steering an automobile straight ahead, positive linear acceleration will change the speed but not the direction of the vehicle.

The weight of the body is the force applied to the body to support it at rest in a uniform gravitational field, g. Using Newton's Second Law of Motion, then

\mathbf{F_W} = -m \mathbf{g} \;

where:

m\; is mass of the body
\mathbf{g}\; is gravitational field (acceleration) vector

For large changes in altitude or with a body of mass significant when compared with the gravitational field source mass, then the gravitational field may no longer be considered uniform and therefore g also changes with time.

See also: Newton's law of universal gravitation and Mass versus weight

The torque from the powerplant is accelerating the body to a desired velocity of motion while lifting the weight of the body, overcoming friction through the powerplant and upon the surface of the body (e.g. rolling resistance and skin friction), and overcoming other drag from the motion of the body through fluids (e.g. air, water). The degree in which the deliverable torque associated with the body overcomes the force of gravity upon the body and yields a net positive linear climbing acceleration, or mechanical advantage, is then

\mbox{MA}=\frac{m \mathbf{a}(t) - F_F - F_D}{-m \mathbf{g}} = \frac{|\mathbf{a}(t)| - \tfrac{1}{m}F_F(m,|\mathbf{v}(t)|) - \tfrac{1}{m}F_D(|\mathbf{v}(t)|)}{|\mathbf{g}|}\;

where:

m\; is mass of the body
|\mathbf{v}(t)|\; is linear speed of the center of mass of the body, changing with time.
\mathbf{a}(t)\; is powerplant acceleration of the center of mass of the body, changing with time.
\mathbf{g}\; is gravitational acceleration of the center of mass of the body.
F_F\; is force of friction within powerplant and upon surface of the body.
F_D\; is force of drag.

If the friction and drag loses are negligible, then the powerplant will convert essentially all its power to either delivering kinetic energy to the body or lifting the weight of the body. To meet this ideal, techniques include low rolling resistance tyres, sufficient tyre inflation, obstacle free path, straight asphalt road, low automotive aerodynamic drag area, well lubricated powertrain and a low loss mechanical transmission to run the engine at a speed that corresponds with the engine peak output power. The mechanical advantage is then simply

\mbox{MA} = \frac{|\mathbf{a}(t)|}{|\mathbf{g}|}\;

Power is only delivered if the powerplant is in motion, and is transmitted to cause the body to be in motion. It is typically assumed here that mechanical transmission allows the powerplant to operate at peak output power. This assumption allows engine tuning to trade power band width and engine mass for transmission complexity and mass. Electric motors do not suffer from this tradeoff. The power advantage or power-to-weight ratio is then

\mbox{P-to-W} = \frac{|\mathbf{a}(t)||\mathbf{v}(t)|}{|\mathbf{g}|}\;

where:

|\mathbf{v}(t)|\; is linear speed of the center of mass of the body.

Power-to-weight ratio is relative to a uniform gravitational field. Normalising to any arbitrary gravitational field yields the specific power or power-to-mass ratio which is then

\mbox{P-to-M} = |\mathbf{a}(t)||\mathbf{v}(t)| = \frac{|\mathbf{\tau}(t)||\mathbf{\omega}(t)|}{m}\;

The power-to-weight ratio is typically calculated from power and mass, although mass is usually measured as weight on a calibrated weighing scale. Values are then expressed in units power per unit force exerted on unit mass in standard gravity. Use of kg (kilogram) and lb (pound) rather than kgf (kilogram-force), SI unit N (Newton) or lbf (pound-force) is common. The value thus expressed is the power-to-mass ratio and not the power-to-weight ratio.

The actual useful power of any traction engine can be calculated using a dynamometer to measure torque and rotational speed, with peak power sustained when transmission and/or operator keeps the product of torque and rotational speed maximised. For jet engines there is often a cruise speed and power can be usefully calculated there, for rockets there is typically no cruise speed, so it is less meaningful.

Peak power of a traction engine occurs at a rotational speed higher than the speed when torque is maximised and below the maximum rated rotational speed - Max RPM. A rapidly falling torque curve would correspond with sharp torque and power curve peaks around their maxima at similar rotational speed, for example a small, lightweight engine with a large turbocharger. A slowing falling or near flat torque curve would correspond with a slowly rising power curve up to a maximum at a rotational speed close to Max RPM, for example a large, heavy multi-cylinder engine suitable for cargo/hauling. A falling torque curve could correspond with a near flat power curve across rotational speeds for smooth handling at different vehicle speeds.

Examples

Engines

Heat engines and heat pumps

Thermal energy is made up from molecular kinetic energy and latent phase energy. Heat engines are able to convert thermal energy in the form of a temperature gradient between a hot source and a cold sink into other desirable mechanical work. Heat pumps take mechanical work to regenerate thermal energy in a temperature gradient.

Heat Engine/Heat Pump type Peak Power Output Power-to-weight ratio Example Use
Wärtsilä RTA96-C 14-cylinder two-stroke Turbo Diesel engine[3] 80,080 kW 108,920 hp 0.03 kW/kg 0.02 hp/lb Emma Mærsk container ship
Suzuki 538 cc V2 4-stroke gas (petrol) outboard Otto engine[4] 19 kW 25 hp 0.27 kW/kg 0.16 hp/lb Runabout boats
DOE/NASA/0032-28 Mod 2 502 cc gas (petrol) Stirling engine[5] 62.3 kW 83.5 hp 0.30 kW/kg 0.18 hp/lb Chevrolet Celebrity[•] 1985
GM 6.6 L Duramax LMM (LYE option) V8 Turbo Diesel engine[1] 246 kW 330 hp 0.65 kW/kg 0.40 hp/lb Chevrolet Kodiak[•], GMC Topkick[•]
Junkers Jumo 205A opposed-piston two-stroke Diesel engine[6] 647 kW 867 hp 1.1 kW/kg 0.66 hp/lb Ju 86C-1 airliner, B&V Ha 139 floatplane
GE LM2500+ marine turboshaft Brayton gas turbine[7] 30,200 kW 40,500 hp 1.31 kW/kg 0.80 hp/lb GTS Millennium cruiseship, QM2 ocean liner
Mazda 13B-MSP Renesis 1.3 L Wankel engine[8] 184 kW 247 hp 1.5 kW/kg 0.92 hp/lb Mazda RX-8[•]
PW R-4360 71.5 L 28-cylinder supercharged Radial engine 3,210 kW 4,300 hp 1.83 kW/kg 1.11 hp/lb B-50 Superfortress, Convair B-36
C-97 Stratofreighter, C-119 Flying Boxcar
Hughes H-4 Hercules "Spruce Goose"
Wright R-3350 54.57 L 18-c s/c Turbo-compound Radial engine 2,535 kW 3,400 hp 2.09 kW/kg 1.27 hp/lb B-29 Superfortress, Douglas DC-7
C-97 S/f prototype, Kaiser-Frazer C-119F
Pattakon OPRE two stroke Diesel engine[9] 50 kW 70 hp 2.3 kW/kg 1.4 hp/lb
O.S. Engines 49-PI Type II 4.97 cc UAV Wankel engine[10] 0.934 kW 1.252 hp 2.8 kW/kg 1.7 hp/lb Model aircraft, Radio-controlled aircraft
GE LM6000 marine turboshaft Brayton gas turbine[11][12] 44,700 kW 59,900 hp 5.67 kW/kg 3.38 hp/lb Peaking power plant
GE CF6-80C2 Brayton high-bypass turbofan jet engine[12] Boeing 747[•], 767, Airbus A300
BMW V10 3L P84/5 2005 gas (petrol) Otto engine[13] 690 kW 925 hp 7.5 kW/kg 4.6 hp/lb Williams FW27 car[•], Formula One auto racing
GE90-115B Brayton turbofan jet engine[14][15] 83,164 kW 111,526 hp 10.0 kW/kg 6.10 hp/lb Boeing 777
PWR RS-24 (SSME) Block II H2 Brayton turbopump[16][17] 63,384 kW 85,000 hp 138 kW/kg 84 hp/lb Space Shuttle (STS-110 and later) [•]
PWR RS-24 (SSME) Block I H2 Brayton turbopump[2] 53,690 kW 72,000 hp 153 kW/kg 93 hp/lb Space Shuttle
  1. Full vehicle power-to-weight ratio shown below

Electric motors/Electromotive generators

An electric motor uses electrical energy to provide mechanical work, usually through the interaction of a magnetic field and current-carrying conductors. By the interaction of mechanical work on an electrical conductor in a magnetic field, electrical energy can be generated.

Electric motor type Weight Peak Power Output Power-to-weight ratio Example Use
Panasonic MSMA202S1G AC servo motor[18] 6.5 kg 14.3 lb 2 kW 2.7 hp 0.31 kW/kg 0.19 hp/lb Conveyor belts, Robotics
Toshiba 660 MVA water cooled 23kV AC turbo generator 1,342 t 2,959,000 lb 660 MW 885,000 hp 0.49 kW/kg 0.30 hp/lb Bayswater, Eraring Coal Power stations
Canopy Tech. Cypress 32 MW 15 kV AC PM generator[19] 33,557 kg 73,981 lb 32 MW 42,913 hp 0.95 kW/kg 0.58 hp/lb Electric Power stations
Toyota Brushless AC Nd Fe B PM motor[20] 36.3 kg 80.0 lb 50 kW 67 hp 1.37 kW/kg 0.84 hp/lb Toyota Prius[•] 2004
Himax HC6332-250 Brushless DC motor[21] 0.45 kg 0.99 lb 1.7 kW 2.28 hp 3.78 kW/kg 2.30 hp/lb Radio controlled cars
Hi-Pa Drive HPD40 Brushless DC wheel hub motor[22] 25 kg 55.1 lb 120 kW 161 hp 4.8 kW/kg 2.92 hp/lb Mini QED HEV, Ford F150 HEV
ElectriFly GPMG4805 Brushless DC[23] 1.48 kg 3.26 lb 8.4 kW 11.26 hp 5.68 kW/kg 3.45 hp/lb Radio-controlled aircraft
  1. Full vehicle power-to-weight ratio shown below

Fluid engines and fluid pumps

Fluids (liquid and gas) can be used to transmit and/or store energy using pressure and other fluid properties. Hydraulic (liquid) and pneumatic (gas) engines convert fluid pressure into other desirable mechanical or electrical work. Fluid pumps convert mechanical or electrical work into movement or pressure changes of a fluid, or storage in a pressure vessel.

Fluid Powerplant type Dry Weight Peak Power Output Power-to-weight ratio
PlatypusPower Q2/200 hydroelectric turbine[24] 43 kg 95 lb 2 kW 2.7 hp 0.047 kW/kg 0.029 hp/lb
PlatypusPower PP20/200 hydroelectric turbine[24] 330 kg 728 lb 20 kW 27 hp 0.060 kW/kg 0.037 hp/lb
Atlas Copco LZL 35 pneumatic motor[25] 20 kg 44.1 lb 6.5 kW 8.7 hp 0.33 kW/kg 0.20 hp/lb
Atlas Copco LZB 14 pneumatic motor[26] 0.30 kg 0.66 lb 0.16 kW 0.22 hp 0.53 kW/kg 0.33 hp/lb
Bosch 0 607 954 307 pneumatic motor[27] 0.32 kg 0.71 lb 0.1 kW 0.13 hp 0.31 kW/kg 0.19 hp/lb
Atlas Copco LZB 46 pneumatic motor[28] 1.2 kg 2.65 lb 0.84 kW 1.13 hp 0.7 kW/kg 0.43 hp/lb
Bosch 0 607 957 307 pneumatic motor[27] 1.7 kg 3.7 lb 0.74 kW 0.99 hp 0.44 kW/kg 0.26 hp/lb
SAI GM7 radial piston hydraulic motor[29] 300 kg 661 lb 250 kW 335 hp 0.83 kW/kg 0.50 hp/lb
SAI GM3 radial piston hydraulic motor[30] 15 kg 33 lb 15 kW 20 hp 1 kW/kg 0.61 hp/lb

Thermoelectric generators and electrothermal actuators

A variety of effects can be harnessed to produce thermoelectricity, thermionic emission, pyroelectricity and piezoelectricity. Electrical resistance and ferromagnetism of materials can be harnessed to generate thermoacoustic energy from an electric current.

Thermoelectric Powerplant type Dry Weight Peak Power Output Power-to-weight ratio Example Use
Teledyne 238Pu GPHS-RTG 1980[31][32] 56 kg 123 lb 285 We 0.39 hp 5.09 W/kg 0.003 hp/lb Galileo probe, New Horizons probe
Boeing 238Pu MMRTG MSL[32] 44.1 kg 97.2 lb 123 We 0.16 hp 2.79 W/kg 0.002 hp/lb Mars Science Laboratory

Electrochemical (galvanic) and electrostatic cell systems

(Closed cell) batteries

All electrochemical cell batteries deliver a changing voltage as their chemistry changes from "charged" to "discharged". A nominal output voltage and a cutoff voltage are typically specified for a battery by its manufacturer. The output voltage falls to the cutoff voltage when the battery becomes "discharged". The nominal output voltage is always less than the open-circuit voltage produced when the battery is "charged". The temperature of a battery can affect the power it can deliver, where lower temperatures reduce power. Total energy delivered from a single charge cycle is affected by both the battery temperature and the power it delivers. If the temperature lowers or the power demand increases, the total energy delivered at the point of "discharge" is also reduced.

Battery discharge profiles are often described in terms of a factor of battery capacity. For example a battery with a nominal capacity quoted in ampere-hours (Ah) at a C/10 rated discharge current (derived in amperes) may safely provide a higher discharge current - and therefore higher power-to-weight ratio - but only with a lower energy capacity. Power-to-weight ratio for batteries is therefore less meaningful without reference to corresponding energy-to-weight ratio and cell temperature.

Battery type Volts Temp. Energy-to-weight ratio Power-to-weight ratio
Energizer 675 Mercury Free Zinc-air battery[33] 1.4V 21 °C 1,645 kJ/kg to 0.9 V 1.65 W/kg 2.24 mA
GE Durathon™ NaMx A2 UPS Molten salt battery[34] 54.2V -40–65°C 342 kJ/kg to 37.8 V 15.8 W/kg C/6 (76 A)
Panasonic R03 AAA Zinc–carbon battery[35][36] 1.5 V 20±2 °C 47 kJ/kg 20 mA to 0.9 V 3.3 W/kg 20 mA
88 kJ/kg 150 mA to 0.9 V 24 W/kg 150 mA
Eagle-Picher SAR-10081 60Ah 22-cell Nickel–hydrogen battery[37] 27.7 V 10 °C 192 kJ/kg C/2 to 22 V 23 W/kg C/2
165 kJ/kg C/1 to 22 V 46 W/kg C/1
ClaytonPower 400Ah Lithium-ion battery[38][39] 12V 617 kJ/kg 85.7 W/kg C/1 (175 A)
Energizer 522 Prismatic Zn–MnO2 Alkaline battery[40] 9 V 21 °C 444 kJ/kg 25 mA to 4.8 V 4.9 W/kg 25 mA
340 kJ/kg 100 mA to 4.8 V 19.7 W/kg 100 mA
221 kJ/kg 500 mA to 4.8 V 99 W/kg 500 mA
Panasonic HHR900D 9.25Ah Nickel–metal hydride battery[41] 1.2 V 20 °C 209.65 kJ/kg to 0.7 V 11.7 W/kg C/5
58.2 W/kg C/1
116 W/kg 2C
URI 1418Ah replaceable anode Aluminium–air battery model[42][43] 244.8 V 60 °C 4680 kJ/kg 130.3 W/kg (142 A)
LG Chemical/CPI E2 6Ah LiMn2O4 Lithium-ion polymer battery[44][45] 3.8 V 25 °C 530.1 kJ/kg C/2 to 3.0 V 71.25 W/kg
513 kJ/kg 1C to 3.0 V 142.5 W/kg
Saft 45E Fe Super-Phosphate Lithium iron phosphate battery[46] 3.3 V 25 °C 581 kJ/kg C to 2.5 V 161 W/kg
560 kJ/kg 1.14 C to 2.0 V 183 W/kg
0.73 kJ/kg 2.27 C to 1.5 V 367 W/kg
Energizer CH35 C 1.8Ah Nickel–cadmium battery[47] 1.2 V 21 °C 152 kJ/kg C/10 to 1 V 4 W/kg C/10
147.1 kJ/kg 5C to 1 V 200 W/kg 5 C
Firefly Energy Oasis FF12D1-G31 6-cell 105Ah VRLA battery[48] 12 V 25 °C 142 kJ/kg C/10 to 7.2 V 4 W/kg C/10
-1 8 °C 7 kJ/kg CCA to 7.2V 234 W/kg CCA (625A)
0 °C 9 kJ/kg CA to 7.2 V 300 W/kg CA (800 A)
Panasonic CGA103450A 1.95Ah LiCoO2 Lithium-ion battery[49] 3.7 V 20 °C 666 kJ/kg C/5.3 to 2.75 V 35 W/kg C/5.3
0 °C 633 kJ/kg C/1 to 2.75 V 176 W/kg C/1
20 °C 655 kJ/kg C/1 to 2.75 V 182 W/kg C/1
20 °C 641 kJ/kg 2C to 2.75 V 356 W/kg 2C
Electric Fuel Battery Corp. UUV 120Ah Zinc–air fuel cell[50] 630 kJ/kg 500 W/kg C/1
Sion Power 2.5Ah Li–S Lithium-ion battery[51] 2.15 V 25 °C 1260 kJ/kg 70 W/kg C/5
1209 kJ/kg 672 W/kg 2C
Maxell / Yuasa / AIST Nickel–metal hydride lab prototype[52] 45 °C 980 W/kg
Toshiba SCiB cell 4.2Ah Li2TiO3 Lithium-ion battery[53][54] 2.4 V 25 °C 242 kJ/kg 67.2 W/kg C/1
218 kJ/kg 4000 W/kg 12C
Ionix Power Systems LiMn2O4 Lithium-ion battery lab model[55] lab 270 kJ/kg 1700 W/kg
lab 29 kJ/kg 4900 W/kg
A123 Systems 26650 Cell 2.3Ah LiFePO4 Lithium ion battery[56][57] 3.3 V -20 °C 347 kJ/kg C/1 to 2V 108 W/kg C/1
0 °C 371 kJ/kg C/1 to 2 V 108 W/kg C/1
25 °C 390 kJ/kg C/1 to 2 V 108 W/kg C/1
25 °C 390 kJ/kg 27C to 2 V 3300 W/kg 27C
25 °C 57 kJ/kg 32C to 2 V 5657 W/kg 32C
Saft VL 6Ah Lithium-ion battery[58] 3.65 V -20 °C 154 kJ/kg 30C to 2.5 V 41.4 W/kg 30C (180 A)
182 kJ/kg 1C to 2.5 V 67.4 W/kg 1C
25 °C 232 kJ/kg 1C to 2.5 V 64.4 W/kg 1C
233 kJ/kg 58.3C to 2.5 V 3757 W/kg 58.3C (350A)
34 kJ/kg 267C to 2.5 V 17176 W/kg 267C (1.6kA)
4.29 kJ/kg 333C to 2.5 V 21370 W/kg 333C (2kA)

Electrostatic, electrolytic and electrochemical capacitors

Capacitors store electric charge onto two electrodes separated by an electric field semi-insulating (dielectric) medium. Electrostatic capacitors feature planar electrodes onto which electric charge accumulates. Electrolytic capacitors use a liquid electrolyte as one of the electrodes and the electric double layer effect upon the surface of the dielectric-electrolyte boundary to increase the amount of charge stored per unit volume. Electric double-layer capacitors extend both electrodes with a nanopourous material such as activated carbon to significantly increase the surface area upon which electric charge can accumulate, reducing the dielectric medium to nanopores and a very thin high permittivity separator.

While capacitors tend not to be as temperature sensitive as batteries, they are significantly capacity constrained and without the strength of chemical bonds suffer from self-discharge. Power-to-weight ratio of capacitors is usually higher than batteries because charge transport units within the cell are smaller (electrons rather than ions), however energy-to-weight ratio is conversely usually lower.

Capacitor type Capacity Volts Temp. Energy-to-weight ratio Power-to-weight ratio
ACT Premlis Lithium ion capacitor[59] 2000 F 4.0 V 25 °C 54 kJ/kg to 2.0 V 44.4 W/kg @ 5 A
31 kJ/kg to 2.0 V 850 W/kg @ 10 A
Nesccap Electric double-layer capacitor[60] 5000 F 2.7 V 25 °C 19.58 kJ/kg to 1.35 V 5.44 W/kg C/1 (1.875 A)
5.2 kJ/kg to 1.35 V 5,200 W/kg[61] @ 2,547A
EEStor EESU barium titanate supercapacitor[62] 30.693 F 3500 V 85 °C 1471.98 kJ/kg 80.35 W/kg C/5
1471.98 kJ/kg 8,035 W∕kg 20 C

Fuel cell stacks and flow cell batteries

Fuel cells and flow cells, although perhaps using similar chemistry to batteries, have the distinction of not containing the energy storage medium or fuel. With a continuous flow of fuel and oxidant, available fuel cells and flow cells continue to convert the energy storage medium into electric energy and waste products. Fuel cells distinctly contain a fixed electrolyte whereas flow cells also require a continuous flow of electrolyte. Flow cells typically have the fuel dissolved in the electrolyte.

Fuel cell type Dry weight Power-to-weight ratio Example Use
Redflow Power+BOS ZB600 10kWh ZBB[63] 900 kg 5.6 W/kg (9.3 W/kg peak) Rural Grid support
Ceramic Fuel Cells BlueGen MG 2.0 CHP SOFC[64] 200 kg 10 W/kg
15 W/kg CHP
MTU Friedrichshafen 240 kW MCFC HotModule 2006 20 t 12 W/kg
Smart Fuel Cell Jenny 600S 25W DMFC[65] 1.7 kg 14.7 W/kg Portable military electronics
UTC Power PureCell 400 kW PAFC[66] 27,216 kg 14.7 W/kg
GEFC 50V50A-VRB Vanadium redox battery[67] 80 kg 31.3 W/kg (125 W/kg peak)
Ballard Power Systems Xcellsis HY-205 205 kW PEMFC[68] 2,170 kg 94.5 W/kg Mercedes-Benz Citaro O530BZ[•]
UTC Power/NASA 12 kW AFC[69] 122 kg 98 W/kg Space Shuttle orbiter[•]
Ballard Power Systems FCgen-1030 1.2 kW CHP PEMFC[70] 12 kg 100 W/kg Residential cogeneration
Ballard Power Systems FCvelocity-HD6 150 kW PEMFC[70] 400 kg 375 W/kg Bus and heavy duty
Honda 2003 43 kW FC Stack PEMFC[71][•] 43 kg 1000 W/kg Honda FCX Clarity[•]
Lynntech, Inc. PEMFC lab prototype[72] 347 g 1,500 W/kg
  1. Full vehicle power-to-weight ratio shown below

Photovoltaics

Photovoltaic Panel type Power-to-weight ratio
Thyssen Solartec 128W Nanocrystalline Si Triplejunction PV module[73] 6 W/kg
Suntech/UNSW HiPerforma PLUTO220-Udm 220W Ga-F22 Polycrystalline Si PV module[74] 13.1 W/kg STP
9.64 W/kg nominal
Global Solar PN16015A 62W CIGS polycrystalline thin film PV module[75] 40 W/kg
Able (AEC) PUMA 6 kW GaInP2/GaAs/Ge-on-Ge Triplejunction PV array[76] 65 W/kg
Current spacecraft grade ~77 W/kg[77]
ITO/InP on Kapton foil 2000 W/kg[78]

Vehicles

Power-to-weight ratios for vehicles are usually calculated using Curb weight (for cars) or wet weight (for motorcycles) – in other words, excluding weight of the driver and any cargo. This could be slightly misleading, especially with regard to motorcycles, where the driver might weigh 1/3 to 1/2 as much as the vehicle itself. In the sport of competitive cycling athlete's performance is increasingly being expressed in VAMs and thus as a power-to-weight ratio in W/kg. This can be measured through the use of a bicycle powermeter or calculated from measuring incline of a road climb and the rider's time to ascend it.[79]

Utility and practical vehicles

Most vehicles are designed to meet passenger comfort and cargo carrying requirements. Different designs trade off power-to-weight ratio to increase comfort, cargo space, fuel economy, emissions control, energy security and endurance. Reduced drag and lower rolling resistance in a vehicle design can facilitate increased cargo space without increase in the (zero cargo) power-to-weight ratio. This increases the role flexibility of the vehicle. Energy security considerations can trade off power (typically decreased) and weight (typically increased), and therefore power-to-weight ratio, for fuel flexibility or drive-train hybridisation. Some utility and practical vehicle variants such as hot hatches and sports-utility vehicles reconfigure power (typically increased) and weight to provide the perception of sports car like performance or for other psychological benefit.

Notable low ratio
Vehicle Power Weight Power-to-weight ratio
Benz Patent Motorwagen 954 cc 1886[80] 560 W / 0.75 bhp 265 kg / 584 lb 2.1 W/kg / 779 lb/hp
Stephenson's Rocket 0-2-2 steam locomotive with tender 1829[81] 15 kW / 20 bhp 4,320 kg / 9524 lb 3.5 W/kg / 476 lb/hp
CBQ Zephyr streamliner diesel locomotive with railcars 1934[82] 492 kW / 660 bhp 94 t / 208,000 lb 5.21 W/kg / 315 lb/hp
Alberto Contador's Verbier climb 2009 Tour de France on Specialized bike[79] 420 W / 0.56 bhp 62 kg / 137 lb 6.7 W/kg / 245 lb/hp
Force Motors Minidor Diesel 499 cc auto rickshaw[83][84] 6.6 kW / 8.8 bhp 700 kg / 1543 lb 9 W/kg / 175 lb/hp
PRR Q2 4-4-6-4 steam locomotive with tender 1944 5,956 kW / 7,987 bhp 475.9 t / 1,049,100 lb 12.5 W/kg / 131 lb/hp
Mercedes-Benz Citaro O530BZ H2 fuel cell bus 2002[85] 205 kW / 275 bhp 14,500 kg / 32,000 lb 14.1 W/kg / 116 lb/hp
TGV BR Class 373 high-speed electric locomotive 1993 12,240 kW / 16,414 bhp 816 t / 1,798,972 lb 15 W/kg / 110 lb/hp
General Dynamics M1 Abrams Main battle tank 1980[86] 1,119 kW / 1500 bhp 55.7 t / 122,800 lb 20.1 W/kg / 81.9 lb/hp
BR Class 43 high-speed diesel electric locomotive 1975 1,678 kW / 2,250 bhp 70.25 t / 154,875 lb 23.9 W/kg / 69 lb/hp
GE AC6000CW diesel electric locomotive 1996 4,660 kW / 6,250 bhp 192 t / 423,000 lb 24.3 W/kg / 68 lb/hp
BR Class 55 Napier Deltic diesel electric locomotive 1961 2,460 kW / 3,300 bhp 101 t / 222,667 lb 24.4 W/kg / 68 lb/hp
International CXT 2004[87] 164 kW / 220 bhp 6,577 kg / 14500 lb 25 W/kg / 66 lb/hp
Ford Model T 2.9 L flex-fuel 1908 15 kW / 20 bhp 540 kg / 1,200 lb 28 W/kg / 60 lb/hp
TH!NK City 2008[88] 30 kW / 40 bhp 1038 kg / 2,288 lb 28.9 W/kg / 56.9 lb/hp
Messerschmitt KR200 Kabinenroller 191 cc 1955 6 kW / 8.2 bhp 230 kg / 506 lb 30 W/kg / 50 lb/hp
Wright Flyer 1903 9 kW / 12 bhp 274 kg / 605 lb 33 W/kg / 50 lb/hp
Tata Nano 624 cc 2008 26 kW / 35 bhp 635 kg / 1,400 lb 41.0 W/kg / 40 lb/hp
Bombardier JetTrain high-speed gas turbine-electric locomotive 2000[89] 3,750 kW / 5,029 bhp 90,750 kg / 200,000 lb 41.2 W/kg / 39.8 lb/hp
Suzuki MightyBoy 543 cc 1988 23 kW / 31 bhp 550 kg / 1,213 lb 42 W/kg / 39 lb/hp
Mitsubishi i MiEV 2009[90] 47 kW / 63 bhp 1,080 kg / 2,381 lb 43.5 W/kg / 37.8 lb/hp
Holden FJ 2,160 cc 1953[91] 44.7 kW / 60 bhp 1,021 kg / 2,250 lb 43.8 W/kg / 37.5 lb/hp
Chevrolet Kodiak/GMC Topkick LYE 6.6 L 2005[1][92] 246 kW / 330 bhp 5126 kg / 11,300 lb 48 W/kg / 34.2 lb/hp
DOE/NASA/0032-28 Chevrolet Celebrity 502 cc ASE Mod II 1985[5] 62.3 kW / 83.5 bhp 1,297 kg / 2,860 lb 48.0 W/kg / 34.3 lb/hp
Suzuki Alto 796 cc 2000 35 kW / 46 bhp 720 kg / 1,587 lb 49 W/kg / 35 lb/hp
Land Rover Defender 2.4 L 1990[93] 90 kW / 121 bhp 1,837 kg / 4,050 lb 49 W/kg / 33 lb/hp
Common power
Vehicle Power Weight Power-to-weight ratio
Toyota Prius 1.8 L 2010 (petrol only)[94] 73 kW / 98 bhp 1,380 kg / 3,042 lb 53 W/kg / 31 lb/hp
Bajaj Platina Naked 100 cc 2006[95] 6 kW / 8 bhp 113 kg / 249 lb 53 W/kg / 31 lb/hp
Subaru R2 type S 2003[96] 47 kW / 63 bhp 830 kg / 1,830 lb 57 W/kg / 29 lb/hp
Ford Fiesta ECOnetic 1.6 L TDCi 5dr 2009[97] 66 kW / 89 bhp 1,155 kg / 2,546 lb 57 W/kg / 29 lb/hp
Volvo C30 1.6D DRIVe S/S 3dr Hatch 2010[98] 80 kW / 108 bhp 1,347 kg / 2,970 lb 59.4 W/kg / 27.5 lb/hp
Ford Focus ECOnetic 1.6 L TDCi 5dr Hatch 2009[99] 81 kW / 108 bhp 1,357 kg / 2,992 lb 59.7 W/kg / 27 lb/hp
Ford Focus 1.8 L Zetec S TDCi 5dr Hatch 2009[100] 84 kW / 113 bhp 1,370 kg / 3,020 lb 61 W/kg / 27 lb/hp
Honda FCX Clarity 4 kg Hydrogen 2008[101] 100 kW / 134 bhp 1,600 kg / 3,528 lb 63 W/kg / 26 lb/hp
Hummer H1 6.6 L V8 2006[102] 224 kW / 300 bhp 3,559 kg / 7,847 lb 63 W/kg / 26 lb/hp
Audi A2 1.4 L TDI 90 type S 2003[103] 66 kW / 89 bhp 1,030 kg / 2,270 lb 64 W/kg / 25 lb/hp
Opel/Vauxhall/Holden/Chevrolet Astra 1.7 L CTDi 125 2010[104] 92 kW / 123 bhp 1,393 kg / 3,071 lb 66 W∕kg / 24.9 lb∕hp
Mini (new) Cooper 1.6D 2007[105] 81 kW / 108 bhp 1,185 kg / 2,612 lb 68 W/kg / 24 lb/hp
Toyota Prius 1.8 L 2010 (electric boost)[94] 100 kW / 134 bhp 1,380 kg / 3,042 lb 72 W/kg / 23 lb/hp
Ford Focus 2.0 L Zetec S TDCi 5dr Hatch 2009[106] 100 kW / 134 bhp 1,370 kg / 3,020 lb 73 W/kg / 23 lb/hp
Toyota Venza I4 2.7 L FWD 2009[107] 136 kW / 182 bhp 1,706 kg / 3,760 lb 80 W/kg / 20.7 lb/hp
Ford Focus 2.0 L Zetec S 5dr Hatch 2009[108] 107 kW / 143 bhp 1,327 kg / 2,926 lb 81 W/kg / 20 lb/hp
Fiat Grande Punto 1.6 L Multijet 120 2005[109] 88 kW / 118 bhp 1,075 kg / 2,370 lb 82 W/kg / 20 lb/hp
Mini (classic) 1275GT 1969 57 kW / 76 bhp 686 kg / 1,512 lb 83 W/kg / 20 lb/hp
Opel/Vauxhall/Holden/Chevrolet Astra 2.0 L CTDi 160 2010[110] 118 kW / 158 bhp 1,393 kg / 3,071 lb 85 W∕kg / 19.4 lb∕hp
Subaru Legacy/Liberty 2.0R 2005[111] 121 kW / 162 bhp 1,370 kg / 3,020 lb 88 W/kg / 19 lb/hp
Subaru Outback 2.5i 2008[112] 130.5 kW / 175 bhp 1,430 kg / 3,153 lb 91 W/kg / 18 lb/hp
Smart Fortwo 1.0 L Brabus 2009[113] 72 kW / 97 bhp 780 kg / 1,720 lb 92 W/kg / 18 lb/hp
Ford Focus 2.0 auto 2007[114] 104.4 kW / 140 bhp 1,198 kg / 2,641 lb 87.1 W/kg / 19 lb/hp
Toyota Venza V6 3.5 L AWD 2009[107] 200 kW / 268 bhp 1,835 kg / 4,045 lb 109 W/kg / 15 lb/hp
Toyota Venza I4 2.7 L FWD 2009[107] with Lotus mass reduction[115] 136 kW / 182 bhp 1,210 kg / 2,667 lb 112.2 W/kg / 14.7 lb/hp
Toyota Hilux V6 DOHC 4 L 4×2 Single Cab Pickup ute 2009[116] 175 kW / 235 bhp 1,555 kg / 3,428 lb 112.5 W/kg / 14.6 lb/hp
Toyota Venza V6 3.5 L FWD 2009[107] 200 kW / 268 bhp 1,755 kg / 3,870 lb 114 W/kg / 14.4 lb/hp
Performance luxury, roadsters and mild sports

Some utility and practical vehicles are designed for, as BMW would say,[117] sheer driving pleasure. Increased engine performance is a consideration, but also other features associated with luxury vehicles. Longitudinal engines are common. Bodies vary from hot hatches, sedans (saloons), coupés, convertibles and roadsters. Mid-range dual-sport and cruiser motorcycles tend to have similar power-to-weight ratios.

Vehicle Power Weight Power-to-weight ratio
Mini (new) Cooper 1.6T S JCW 2008[118] 155 kW / 208 bhp 1205 kg / 2657 lb 129 W/kg / 13 lb/hp
Mazda RX-8 1.3 L Wankel 2003 173 kW / 232 bhp 1309 kg / 2888 lb 141 W/kg / 12 lb/hp
Holden Statesman/Caprice / Buick Park Avenue / Daewoo Veritas 6 L V8 2007[119] 270 kW / 362 bhp 1891 kg / 4170 lb 143 W/kg / 12 lb/hp
Kawasaki KLR650 Gasoline DualSport 650 cc 26 kW / 35 bhp 182 kg / 401 lb 143 W/kg / 11 lb/hp
NATO HTC M1030M1 Diesel/Jet fuel DualSport 670 cc[120] 26 kW / 35 bhp 182 kg / 401 lb 143 W/kg / 11 lb/hp
Harley-Davidson FLSTF Softail Fat Boy Cruiser 1,584 cc 2009[121] 47 kW / 63 bhp 324 kg / 714 lb 145 W/kg / 11.3 lb/hp
BMW 7 Series 760Li 6 L V12 2006[122] 327 kW / 439 bhp 2250 kg / 4960 lb 145 W/kg / 11 lb/hp
Subaru Impreza WRX STi 2.0 L 2008[123] 227 kW / 304 bhp 1530 kg / 3373 lb 148 W/kg / 11 lb/hp
Honda S2000 roadster 1999 183.88 kW / 240 bhp 1250 kg / 2723 lb 150 W/kg / 11 lb/hp
Ford Mustang 2005 4.0 L SOHC V6 231 kW / 310 bhp 1497 kg / 3300 lb 154 W/kg / 10.65 lb/hp
GMH HSV Clubsport / GMV VXR8 / GMC CSV CR8 / Pontiac G8 6 L V8 2006[124] 317 kW / 425 bhp 1831 kg / 4037 lb 173 W/kg / 9.5 lb/hp
Tesla Roadster 2011[125] 215 kW / 288 bhp 1235 kg / 2723 lb 174 W/kg / 9.5 lb/hp

Sports vehicles and aircraft

Power-to-weight ratio is an important vehicle characteristic that affects the acceleration and handling - and therefore the driving enjoyment - of any sports vehicle. Aircraft also depend on high power-to-weight ratio to achieve sufficient lift.

Vehicle Power Weight Power-to-weight ratio
Lotus Elise SC 2008 163 kW / 218 bhp 910 kg / 2006 lb 179 W/kg / 9 lb/hp
Ferrari Testarossa 1984 291 kW / 390 bhp 1506 kg / 3320 lb 193 W/kg / 9 lb/hp
Artega GT[126] 220 kW / 300 bhp 1100 kg / 2425 lb 200 W/kg / 8 lb/hp
Lotus Exige GT3 2006[127] 202.1 kW / 271 bhp 980 kg / 2160 lb 206 W/kg / 8 lb/hp
Bombardier Dash 8 Q400 turboprop airliner[128] 3,781 kW / 5,071 bhp 17,185 kg / 37,888 lb 220 W/kg / 7.5 lb/hp
Chevrolet Corvette C6[129] 321 kW / 430 bhp 1441 kg / 3177 lb 223 W/kg / 7 lb/hp
Suzuki V-Strom 650 V-twin DualSport 650 cc 50 kW / 67 bhp 194 kg / 427 lb 258 W/kg / 6.4 lb/hp
Chevrolet Corvette C6 Z06[129] 376 kW / 505 bhp 1421 kg / 3133 lb 265 W/kg / 6 lb/hp
Porsche 911 GT2 2007 390 kW / 523 bhp 1440 kg / 3200 lb 271 W/kg / 6.1 lb/hp
Lamborghini Murciélago LP 670-4 SV 2009[130] 493 kW / 661 bhp 1550 kg / 3417 lb 318 W/kg / 5.1 lb/hp
McLaren F1 GT 1997[131] 467.6 kW / 627 bhp 1220 kg / 2690 lb 403 W/kg / 4 lb/hp
Supermarine Spitfire Fighter aircraft 1936 1,096 kW / 1,470 bhp 2,309 kg / 5,090 lb 475 W/kg / 3.46 lb/hp
Messerschmitt Bf 109 Fighter aircraft 1935 1,085 kW / 1,455 bhp 2,247 kg / 4,954 lb 483 W/kg / 3.40 lb/hp
Thunderbolt Land speed record car 3504 kW / 4700 bhp 7 t / 15432 lb 500 W/kg / 3.28 lb/hp
Ferrari FXX 2005 597 kW / 801 bhp 1155 kg / 2546 lb 517 W/kg / 3.2 lb/hp
Polaris Industries Assault Snowmobile 2009[132] 115 kW / 154 bhp 221 kg / 487 lb 523 W/kg / 3.16 lb/hp
Ultima GTR 720 2006[133] 536.9 kW / 720 bhp 920 kg / 2183 lb 583 W/kg / 3 lb/hp
Honda CBR1000RR 2009 133 kW / 178 bhp 199 kg / 439 lb 668 W/kg / 2.5 lb/hp
Ariel Atom 500 V8 2011 372 kW / 500 bhp 550 kg / 1212 lb 676.3 W/kg / 2.45 lb/hp
KillaCycle Drag racing electric motorcycle 260 kW / 350 bhp 281 kg / 619 lb 925 W/kg / 1.77 lb/hp
MTT Turbine Superbike 2008[134] 213.3 kW / 286 bhp 227 kg / 500 lb 940 W/kg / 1.75 lb/hp
Vyrus 987 C3 4V V supercharged motorcycle 2010[135] 157.3 kW / 211 bhp 158 kg / 348.3 lb 996 W/kg / 1.65 lb/hp
BMW Williams FW27 Formula One 2005[136] 690 kW / 925 bhp 600 kg / 1323 lb 1150 W/kg / 1.43 lb/hp
Honda RC211V MotoGP 2004-6 176.73 kW / 237 bhp 148 kg / 326 lb 1194 W/kg / 1.37 lb/hp
Boeing 747-300[11] at Mach 0.84 cruise, 35,000 ft altitude 245 MW / 328,656 bhp 178.1 t / 392,800 lb 1376 W/kg / 1.20 lb/hp
John Force Racing Funny Car NHRA Drag Racing 2008[137] 5,963.60 kW / 8,000 bhp 1043 kg / 2,300 lb 5717 W/kg / 0.30 lb/hp
Supersonic vehicles

Some sports and aerospace vehicles are capable of exceeding the speed of sound. Vehicles in this class must account for transonic wave drag, shock waves and aerodynamic heating. Turbojet, turbofan, ramjet, afterburner and rocket propulsion is common. Note that with rockets and air breathing jet engines, vehicle power is proportional to vehicle speed, since rockets(and to a lesser extent air breathing jet engines) give a thrust that is completely independent of speed, this means that there is no upper limit to any particular rocket's power-to-weight ratio provided it has been given sufficient initial speed.

Vehicle Power Weight Power-to-weight ratio
Space Shuttle Endeavour (OV-105)[17][138] 190 MW / 255,000 bhp 78 t / 172,000 lb 2,437 W/kg / 0.7 lb/hp
Aérospatiale/BAC Concorde 1969 at Mach 2.02 supercruise full thrust 330 MW / 443,143 bhp 78.7 t / 173,500 lb 4,199 W/kg / 0.39 lb/hp
Thrust Super Sonic Car 82 MW / 110,000 bhp 10.5 t / 23,149 lb 7,812 W/kg / 0.21 lb/hp
F-35 Lightning II Multirole combat aircraft 2006 at Mach 1.67 full thrust 110 MW / 146,922 bhp 13,300 kg / 29,300 lb 8,238 W/kg / 0.20 lb/hp
Sukhoi Su-35BM Multirole combat aircraft 2008 at Mach 2.25 full thrust 188.5 MW / 252,842 bhp 18,400 kg / 40,500 lb 10,247 W/kg / 0.16 lb/hp
Lockheed SR-71 Blackbird Surveillance aircraft 1966 at Mach 3.2, 290 kN thrust 318.3 MW / 426,853 bhp 30,600 kg / 67,461 lb 10,402 W/kg / 0.16 lb/hp
Sukhoi T-50 Stealth multirole fighter aircraft 2010 at Mach 2, 294 kN thrust 201 MW / 270,620 bhp 18,500 kg / 40,786 lb 10,908 W/kg / 0.15 lb/hp
F-22 Raptor Air superiority fighter aircraft 1990 at Mach 2.25, 312 kN thrust[139] 241 MW / 323,088 bhp 19,700 kg / 43,430 lb 12,230 W/kg / 0.13 lb/hp
Rockwell X-30 scramjet SSTO spaceplane 1986 at Mach 30, 1.4 MN thrust (proposed) 14 GW / 19,300,000 bhp 136 t / 300,000 lb 105,740 W∕kg / 0.016 lb/hp
Space Shuttle Endeavour (OV-105)[17][138] with SLWT and 2 SRBs[140][141][142] 33 GW / 44,000,000 bhp 280 t / 616,500 lb 118,000 W/kg / 0.014 lb/hp

See also

References

  1. ^ a b c "General Motors 2009 Data Book". September 5, 2008. http://eogld.ecomm.gm.com/images/mediumduty/techspecs/engine.pdf. 
  2. ^ a b Ryan, Richard. "Lessons in Systems Engineering - The SSME Weight Growth History". NASA. http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090004620_2008048278.pdf. 
  3. ^ "The world's most powerful Engine enters service" (Press release). Wärtsilä. 2006-09-12. http://www.wartsila.com/,en,press,0,tradepressrelease,8F51527F-00A3-4C5F-ABEA-B543789ACA1B,26EE6684-06C9-48B3-920A-3B238B7C302A,,.htm. Retrieved 2010-01-12. 
  4. ^ "Suzuki Marine - DF25 - Features and Specifications". Suzuki. http://www.suzukimarine.com/sr_09/df25/features/. Retrieved January 12, 2010. 
  5. ^ a b Noel P. Nightingale (October 1986). "Automotive Stirling Engine - Mod II Design Report". NASA Lewis Research Center. http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19880002196_1988002196.pdf. Retrieved July 16, 2010. 
  6. ^ Jane's 1989, p. 294.
  7. ^ "LM2500+ Marine Gas Turbine". GE Aviation. http://www.geae.com/engines/marine/pdfs/datasheet_lm2500plus.pdf. Retrieved 2010-01-25. 
  8. ^ "Mazda - What Is A Rotary Engine?". Mazda. http://www.mazda.com/mazdaspirit/rotary/about/. Retrieved January 12, 2010. 
  9. ^ "Opposed piston Pulling Rod Engine ( OPRE )". Pattakon. http://www.pattakon.com/pattakonOPRE.htm. Retrieved 2010-01-08. 
  10. ^ "UAV Wankel Engines". O.S. Engines. http://www.osengines.com/engines/osmg1401.html. Retrieved 2010-01-08. 
  11. ^ a b "LM6000 Marine Gas Turbine". GE Aviation. http://www.geae.com/engines/marine/pdfs/datasheet_lm6000.pdf. Retrieved 2010-01-25. 
  12. ^ a b "GE's LM6000 Demonstrates Outstanding Reliability And Availability In First Two Years Of Commercial Service". http://www.geae.com/aboutgeae/presscenter/marine/marine_19950523c.html. Retrieved 2010-01-25. 
  13. ^ "BMW engines". All Formula One Info. http://www.allf1.info/engines/bmw.php. Retrieved 2010-01-08. 
  14. ^ "Model GE90-115B". GE Aviation. http://www.geae.com/engines/commercial/ge90/ge90-115b.html. Retrieved 2010-01-08. 
  15. ^ (French) Jean-Claude Thevenin, Le turboréacteur, moteur des avions à réaction, AAAF, June 2004 (3rd edition).
  16. ^ "NASA Fact Sheet: Space Shuttle Main Engine (SSME) Enhancements". Marshall Space Flight Center, Huntsville, Alabama: NASA. March 2002. http://www.nasa.gov/centers/marshall/pdf/174534main_ssme.pdf. 
  17. ^ a b c "High Performance Liquid Hydrogen Turbopumps". NASA. 1999-02-01. http://www.nasa.gov/offices/oce/llis/0750.html. Retrieved 2010-01-08. 
  18. ^ "Panasonic MINAS-A4 AC Servo - Motor Specifications and Ratings 200V MSMA". http://industrial.panasonic.com/ww/i_e/25000/fa_pro_acs_minas_a4_e/fa_pro_acs_minas_a4_e/a4_16.pdf. Retrieved 2010-01-26. 
  19. ^ "Cypress HPL Series Permanent Magnet Motors - Product Brochure". Canopy Technologies, LLC. http://canopytechnologies.com/uploads/Cypress%20Family-Data%20Sheet.pdf. Retrieved 2010-01-26. 
  20. ^ Jewell, Geraint (2009-09-11). "Permanent Magnet Machines and Actuators". Symposium on Materials for a Sustainable Future. Birmingham, England: Magnetic Materials Group, University of Birmingham. pp. 11–18. http://www.birmingham.ac.uk/Documents/college-eps/metallurgy/research/Jewell.pdf. Retrieved 2010-05-14. 
  21. ^ "Himax Brushless Outrunner Motor HC6332-250". Maxx Products International, Inc.. http://www.maxxprod.com/pdf/HC6320-250.pdf. Retrieved 2010-01-28. 
  22. ^ "Hi-Pa Drive". PML Flightlink. http://www.pmlflightlink.com/motors/hipa_drive.html. Retrieved 2010-03-02. 
  23. ^ "Great Planes ElectriFly RimFire 65cc 80-85-160 Brushless Outrunner Electric Motor". http://manuals.hobbico.com/gpm/gpmg4800-4805-manual.pdf. Retrieved 2010-11-02. 
  24. ^ a b "Platypus Power Micro Hydro Electric Generator - Specifications". Platypus Power. http://www.platypuspower.com.au/240specs.html. Retrieved 2010-01-15. 
  25. ^ "Atlas Copco Air motor catalogue, page 52 - Product data at air pressure 6.3 bar (91 psi) - LZL 35 Unrestricted". Atlas Copco. http://www.atlascopco.co.uk/Images/AirMotor_catalogue.ENG_tcm795-1610751.pdf. Retrieved 2011-09-21. 
  26. ^ "Atlas Copco Tools - LZB 14 Technical data". Atlas Copco. http://www.atlascopco.co.uk/ukus/products/navigationbyproduct/Product.aspx?id=1466515&productgroupid=1401305. Retrieved 2011-09-21. 
  27. ^ a b "Bosch Production Tools - Air Tools - Motors". Bosch. http://www.boschproductiontools.com/iwboptocs2-en/category.htm?ccat_id=125831. Retrieved 2010-01-15. 
  28. ^ "Atlas Copco Tools - LZB 46 Technical data". Atlas Copco. http://www.atlascopco.co.uk/ukus/products/navigationbyproduct/Product.aspx?id=1466765&productgroupid=1401305. Retrieved 2011-09-21. 
  29. ^ SAI. "GM Series - GM7 Hydraulic Motor". SAI. http://www.saispa.com/pdf/gm-7.pdf. Retrieved 2010-01-14. 
  30. ^ SAI. "GM03 Motor - Extremely Compact Unit". SAI. http://www.saispa.com/pdf/gm-03.pdf. Retrieved 2010-01-14. 
  31. ^ Bennett, G.L. (2006). "Space Nuclear Power". Federation of American Scientists. http://www.fas.org/nuke/space/bennett0706.pdf. 
  32. ^ a b Caillat, T. (August 2006). "Development of a New Generation of High-Temperature Thermoelectric Unicouples for Space Applications". NASA, JPL and Caltech. http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/40238/1/06-2720.pdf. 
  33. ^ "Product Datasheet - Energizer 675 ZnAir". Energizer Holdings. 2010-02-15. http://data.energizer.com/PDFs/675.pdf. Retrieved 2010-09-20. 
  34. ^ "GE Durathon Batteries - NaMx Battery System for Telecom Applications". Pennsylvania State University. 2010-09-17. http://www.personal.psu.edu/klm5709/plugin-GE-NaMx-Batteries-ss.pdf. Retrieved 2011-11-24. 
  35. ^ "Zinc Carbon Batteries". Panasonic. August 2009. http://industrial.panasonic.com/www-data/pdf2/AAE4000/AAE4000CE16.pdf. Retrieved February 5, 2010. 
  36. ^ Matsushita Battery Industrial Co., Ltd.;Matsushita Electric Industrial Co., Ltd. (June 25, 1998). "Specification for Zinc-Carbon Dry Battery R03(NB)". Panasonic. http://products.panasonic-industrial.com/downloads/en/R03.pdf. 
  37. ^ EaglePicher Technologies, LLC (February 6, 2003). "Nickel Hydrogen (NiH2) Batteries - Single Pressure Vessel". University of Padua. http://www.die.unipd.it/personale/doc/Benato_Roberto/didattica/corsi/IMPIANTI_ELETTRICI_DI_BORDO_PER_IAS/2_zona_di_transizione/BATTERIE/Batt_SPV.pdf. Retrieved February 5, 2010. 
  38. ^ Clayton Power (2010). "Lithium Ion Battery Packs". Clayton Power. http://www.claytonpower.com/products/lithium-ion-battery/. Retrieved 2010-10-05. 
  39. ^ Clayton Power (2010). "Complete Power Systems - 24VDC/230VAC". Clayton Power. http://www.claytonpower.com/products/complete-power-systems-24v-230v/. Retrieved 2010-10-05. 
  40. ^ "Product Datasheet - Energizer 522 9V". Energizer Holdings. http://data.energizer.com/PDFs/522.pdf. Retrieved February 4, 2010. 
  41. ^ "Nickel Metal Hydride Batteries - Individual Data Sheet - HHR900D". Panasonic. August 2005. http://www.panasonic.com/industrial/includes/pdf/Panasonic_NiMH_HHR900D.pdf. Retrieved February 5, 2010. 
  42. ^ Yang, Shaohua, and Harold Knickle (2002). "Design and analysis of aluminum/air battery system for electric vehicles". Journal of Power Sources 112 (1): 162–173. doi:10.1016/S0378-7753(02)00370-1. ISSN 0378-7753. 
  43. ^ Zhang, Xin, Shao Hua Yang, and Harold Knickle (2004). "Novel operation and control of an electric vehicle aluminum/air battery system". Journal of Power Sources 128 (2): 331–342. doi:10.1016/j.jpowsour.2003.09.058. ISSN 0378-7753. 
  44. ^ LG Chem. (2005-03-24). "E2 General Information". Lucky Goldstar Chemical Ltd.. pp. 1. http://www.lgchem.com/upload/02_Ko/e2%20cell%20specsheet(6ah).pdf. Retrieved 2010-10-01. 
  45. ^ LG Chem. (2009-01-12). "Press Release - LG Chem Battery Cells to Power Chevrolet Volt". Lucky Goldstar Chemical Ltd., CompactPower division. pp. 3. http://www.compactpower.com/Documents/MicrosoftWord-LG_Chem_pressrelease_finalon20080110.pdf. Retrieved 2010-10-01. 
  46. ^ JCI-SAFT (2010 June). "Rechargeable LiFePO4 lithium-ion battery Super-Phosphate VL 45E Fe Very High Energy cell". SAFT Batteries. http://www.saftbatteries.com/doc/Documents/defence/Cube769/VL45EFe.e3741a09-74fd-4df4-8687-12997f445ef5.pdf. Retrieved 2010-10-01. 
  47. ^ "Product Datasheet - Energizer CH35 C". Energizer Holdings. http://data.energizer.com/PDFs/CH35.pdf. Retrieved February 4, 2010. 
  48. ^ "Microcell Technology AGM Deep Cycle Group 31 Battery". FireFly Energy, Inc.. 2009. http://www.fireflyenergy.com/images/stories/pdfs/Group%2031%20Spec%20Sheet%20REV%20-%20110909.pdf. Retrieved February 4, 2010. 
  49. ^ "Lithium Ion Batteries - Individual Data Sheet - CGA103450A". Panasonic. January 2007. http://www.panasonic.com/industrial/battery/oem/images/pdf/Panasonic_LiIon_CGA103450A.pdf. Retrieved February 4, 2010. 
  50. ^ "Mission Extended - Advanced Zinc-Air Battery Technology". Electric Fuel Battery Corporation. 2003-03-30. http://www.efbpower.com/downloads/UAVbro2.pdf. Retrieved 2010-09-15. 
  51. ^ "Sion Power - LiS Spec Sheet". Sion Power. October 3, 2008. http://sionpower.com/pdf/articles/LIS%20Spec%20Sheet%2010-3-08.pdf. Retrieved 11 September 2010. 
  52. ^ Fukunaga, Hiroshi; Kishimi, Mitsuhiro; Matsumoto, Nobuaki; Tanaka, Toshiki; Kishimoto, Tomonori; Ozaki, Tetsuya; Sakai, Tetsuo (2006). "Improvement of Nickel Metal Hydride Battery with Non-foam Nickel Electrode for Hybrid Electric Vehicles Applications". Electrochemistry (Japan) 75 (5): 385–393. ISSN 1344-3542. http://sciencelinks.jp/j-east/article/200610/000020061006A0350302.php. Retrieved February 4, 2010. 
  53. ^ "Rechargeable Battery SCiB - Description". Toshiba Corporation. http://www.scib.jp/en/product/detail.htm. Retrieved 2010-09-11. 
  54. ^ "Rechargeable Battery SCiB - Specifications". Toshiba Corporation. http://www.scib.jp/en/product/spec.htm. Retrieved 2010-09-11. 
  55. ^ "Lithium Ion Battery Research". Ionix Power Systems. http://www.ionixpower.com/lithium_ion_battery.htm. Retrieved February 4, 2010. 
  56. ^ "A123Systems Products". A123 Systems. http://www.a123systems.com/a123/products. Retrieved February 4, 2010. 
  57. ^ "High Power Lithium Ion ANR26650M1A - Datasheet". A123 Systems. http://www.a123systems.com/cms/product/pdf/1/_ANR26650M1A.pdf. Retrieved February 4, 2010. 
  58. ^ JCI-Saft (2009 June). "Rechargeable lithium-ion battery VL 6A Very High Power cell". SAFT Batteries. http://www.saftbatteries.com/doc/Documents/defence/Cube769/VL6A_data_sheet.9ea09188-84ad-4c54-989b-a2206dc28da2.pdf. Retrieved 2010-10-02. 
  59. ^ "Typical Characteristics of Premlis". Advanced Capacitor Technologies, Inc.. http://www.act.jp/eng/premlis/premlis.htm. Retrieved September 9, 2010. 
  60. ^ "Nesccap Ultracapacitor Products - EDLC - Prismatic". Nesscap Co., Ltd.. http://www.nesscap.com/data_nesscap/spec_sheets/Spec%2009.pdf. Retrieved September 10, 2010. 
  61. ^ "Nesccap Ultracapacitor (EDLC)". Nesscap Co., Ltd.. http://www.nesscap.com/products_edlc.htm. Retrieved September 10, 2010. 
  62. ^ US patent 7466536, Weir; Richard Dean & Nelson; Carl Walter, "Utilization of poly(ethylene terephthalate) plastic and composition-modified barium titanate powders in a matrix that allows polarization and the use of integrated-circuit technologies for the production of lightweight ultrahigh electrical energy storage units (EESU)", published 16 December 2008, issued 16 December 2008, assigned to EEStor, Inc 
  63. ^ "Redflow Power+BOS ZB600 Stand Alone Power System". Redflow. March 2010. http://www.redflow.com.au/Files/PowerBOSZB600%20-%20Limited%20Warranty.pdf. Retrieved September 11, 2010. 
  64. ^ "BlueGen Modular Generator - Power + Heat". Ceramic Fuel Cells Ltd.. http://www.cfcl.com.au/Assets/Files/BlueGen_Brochure(ENG_GER)_Mar-09.pdf. Retrieved February 4, 2010. 
  65. ^ "The Jenny fuel cell by SFC". Smart Fuel Cell AG. http://www.sfc.com/en/man-portable-jenny.html. Retrieved February 4, 2010. 
  66. ^ "UTC Power - Model 400 PureCell System". South Windsor, Connecticut, USA: UTC Power. 2008. http://www.utcpower.com/fs/com/Attachments/data_sheets/DS0112_093008.pdf. Retrieved February 4, 2010. 
  67. ^ "GEFC 50V50A-VRB Vanadium Redox Battery Stack". GEFC. 2010. http://www.gefc.com/info/2009112/2009112115605.shtml. Retrieved February 5, 2010. 
  68. ^ "Transportation Fuel Cells - Technical Info.". Fuel Cells 2000. http://www.fuelcells.org/info/charts/TransTechnical.pdf. Retrieved 2010-07-24. 
  69. ^ "Space Orbiter". UTC Power. 2008. http://www.utcpower.com/fs/com/bin/fs_com_Page/0,11491,0115,00.html. Retrieved February 5, 2010. 
  70. ^ a b "PEM Fuel Cell Product Portfolio". Ballard Power Systems. http://www.ballard.com/files/pdf/Spec_Sheets/PEM_FC_Product_Portfolio_docmetrics.pdf. Retrieved February 4, 2010. 
  71. ^ "Press Information Honda Fuel Cell Power FCX". Honda. December 2004. http://world.honda.com/FuelCell/FCX/FCXPK.pdf. Retrieved February 4, 2010. 
  72. ^ Murphy, O.J.; Cisar, A.; Clarke, E. (1998). "Low-cost light weight high power density PEM fuel cell stack". Proceedings of the Symposium on Batteries and Fuel Cells for Portable Applications and Electric Vehicles. INIST. pp. 3829–3840. http://cat.inist.fr/?aModele=afficheN&cpsidt=2439605. 
  73. ^ "Thyssen-Solartec - The photovoltaic roof and façade system". Thyssen Solartec. http://www.thyssen-solartec.de/solartec_uk.pdf. Retrieved 2010-02-13. 
  74. ^ "Suntech HiPerforma Module PLUTO220-Udm PLUTO215-Udm". Suntech Power. http://www.suntech-power.com/images/stories/2010_datasheets/EN/suntech_hiperforma_udm_en.pdf. Retrieved 2010-03-09. 
  75. ^ "GlobalSolar Product Catalog - Power the Possibilities". Global Solar. http://www.globalsolar.com/index.php?option=com_rubberdoc&view=doc&id=47&format=raw. Retrieved 2010-03-09. 
  76. ^ "A Heritage-Technology Rigid Substrate Solar Array for Traditional Applications". Able Engineering Company, Inc.. http://www.aec-able.com/arrays/Resources/PumaSheet.pdf. Retrieved 2010-02-13. 
  77. ^ Rocket and spacecraft propulsion By Martin J. L. Turner
  78. ^ http://apl.aip.org/resource/1/applab/v95/i22/p223503_s1
  79. ^ a b "What is VAM and How to Calculate it?". Cycling Fitness. 2009-07-24. http://www.cyclingfitness.net/what-is-vam-and-how-to-calculate-it/. Retrieved 2010-06-25. 
  80. ^ "1886 Benz Patent Motorwagen". Los Angeles Times (Tribune Company). 2006-06-01. http://www.latimes.com/news/printedition/highway1/la-hy-125mbzbox21jun21,1,3672562.story. 
  81. ^ Karwatka, Dennis, ed. "Robert Stephenson and 19th-Century Transportation Technology". Encyclopædia Britannica. http://www.britannica.com/bps/additionalcontent/18/28339806/Robert-Stephenson-and-19thCentury-Transportation-Technology. Retrieved 2010-01-08. 
  82. ^ Cobb, Harold M. (June 2006). "The Burlington Zephyr Stainless Steel Train". Advanced Materials & Processes: 24–28. http://asmcommunity.asminternational.org/vgn-ext-templating/views/ASM/OpenDocument.jsp?vcmid=b6b1a538b5c81210VgnVCM100000621e010aRCRD. Retrieved 2010-01-12. 
  83. ^ Minidor Diesel 3-seater, Force Motors, http://www.forcemotors.com/media/downloads/DIESEL3SEATER.pdf, retrieved 2010-01-08 
  84. ^ "Balaji Force Minidor Autorickshaw". Balaji Force. http://balajiforce.com/threeWheelers.aspx?id=2. Retrieved 2010-01-08. 
  85. ^ Ally, Jamie; Pryor, Trevor (2007-04-25). "Life-cycle assessment of diesel, natural gas and hydrogen fuel cell bus transportation systems". Journal of Power Sources (Research Institute for Sustainable Energy, Murdoch University, Perth, Western Australia, Australia: Elsevier) 170 (2): 401–411. doi:10.1016/j.jpowsour.2007.04.036. ISSN 0378-7753. 
  86. ^ "Abrams Tank Fact File for the United States Army". US Army. http://www.army.mil/factfiles/equipment/tracked/abrams.html. Retrieved 2011-02-19. 
  87. ^ Leno, Jay (March 2005). "A Tonka Toy comes to life--really big life.". Popular Mechanics. http://www.popularmechanics.com/automotive/jay_leno_garage/1368287.html. 
  88. ^ "TH!NK City - Specifications - Technical Data". TH!NK Global. http://www.thinkev.com/The-THINK-City/Specifications/Technical-data/. Retrieved 2010-09-13. 
  89. ^ "Bombardier Transportation - Rail Vehicles - Intercity/Highspeed - JetTrain". June 2000. http://canadair.ca/en/1_0/1_10/1_10_2_1.jsp?menu=1_0. Retrieved 2010=07=24. 
  90. ^ "About i MiEV". Mitsubishi Motors. 2008 July. http://www.mitsubishi-motors.com/special/ev/whatis/index.html. Retrieved 2010-06-03. 
  91. ^ "Holden FJ Technical Specifications". Unique Cars and Parts. http://www.uniquecarsandparts.com.au/holden_FJ_technical_specifications.htm. Retrieved 2010-01-08. 
  92. ^ Quiroga, Tony (November 2005). "GMC TopKick C4500 by Monroe Truck Equipment - Specs; Hummer This". Car And Driver. http://www.caranddriver.com/reviews/car/05q4/gmc_topkick_c4500_by_monroe_truck_equipment-mini_test_road_test/specs_page_2. Retrieved 2010-01-15. 
  93. ^ "Land Rover Defender 4×4 110 2.4D Hard Top 5dr". What Car?. http://www.whatcar.com/Review/EditionCompare?newOrUsed=New&makeId=11729&modelId=11730&editionId=11781#tabsection3. Retrieved 2010-01-08. 
  94. ^ a b "Toyota Prius 2010 Performance & Specifications". Toyota. http://www.toyota.com/prius-hybrid/specs.html. Retrieved 2010-01-08. 
  95. ^ "Details of Bajaj Platina 100 cc". AutoIndia. http://www.autoindia.com/VehicleStyles/bike-car-details1086.html. Retrieved 2010-01-08. 
  96. ^ "2003 Subaru R2 S Technical specifications". Car Folio. http://www.carfolio.com/specifications/models/car/?car=117601. Retrieved 2010-01-08. 
  97. ^ "Ford Fiesta Hatchback 1.6 TDCi Econetic 5dr". What Car?. http://www.whatcar.com/Review/EditionCompare?newOrUsed=New&makeId=1&modelId=1244&editionId=1507#tabsection3. Retrieved 2010-01-08. 
  98. ^ "Volvo C30 - a Four-Seat Sports Coupé with High Performance". Volvo. http://www.volvocars.com/intl/All-Cars/Volvo-C30/Pages/default.aspx. Retrieved 2010-03-16. 
  99. ^ "Ford Focus Hatchback 1.6 TDCi 110 DPF ECOnetic 5dr". What Car?. http://www.whatcar.com/Review/EditionCompare?newOrUsed=New&makeId=1&modelId=165&editionId=552#tabsection3. Retrieved 2010-01-08. 
  100. ^ "Ford Focus Hatchback 1.8 TDCi Zetec S 5dr". What Car?. http://www.whatcar.com/Review/EditionCompare?newOrUsed=New&makeId=1&modelId=165&editionId=619#tabsection3. Retrieved 2010-01-08. 
  101. ^ "The History of the Honda FCX Clarity, Fuel Cell Electric Vehicle FCEV". Honda. http://corporate.honda.com/environment/fuel_cells.aspx?id=fuel_cells_fcx. Retrieved 2010-01-08. 
  102. ^ "2006 HUMMER H1 specifications". InternetAutoguide.com. http://www.internetautoguide.com/car-specifications/09-int/2006/hummer/h1/index.html. Retrieved 2010-01-08. 
  103. ^ "2003 Audi A2 1.4 TDi Technical specifications". Car Folio. http://www.carfolio.com/specifications/models/car/?car=117601. Retrieved 2010-01-08. 
  104. ^ "Vauxhall Astra Hatchback 1.7 CDTi 125 Elite 5dr". What Car?. http://www.whatcar.com/Review/EditionCompare?newOrUsed=New&makeId=2080&modelId=2199&editionId=31557#tabsection3. Retrieved 2010-07-09. 
  105. ^ "Mini Cooper Hatchback 1.6D 3dr". What Car?. http://www.whatcar.com/Review/EditionCompare?newOrUsed=New&makeId=29021&modelId=29090&editionId=29126#tabsection3. Retrieved 2010-01-08. 
  106. ^ "Ford Focus Hatchback 1.8 TDCi Style 5dr". What Car?. http://www.whatcar.com/Review/EditionCompare?newOrUsed=New&makeId=1&modelId=165&editionId=553#tabsection3. Retrieved 2010-01-08. 
  107. ^ a b c d "Toyota Venza Performance & Specs". Toyota Motor North America. 2010. http://www.toyota.com/venza/specs.html. Retrieved 2010-11-06. 
  108. ^ "Ford Focus Hatchback 2.0 Zetec S 5dr". What Car?. http://www.whatcar.com/Review/EditionCompare?newOrUsed=New&makeId=1&modelId=165&editionId=617#tabsection3. Retrieved 2010-01-08. 
  109. ^ "Fiat Grande Punto Hatchback 1.6 Multijet 120 Sporting 5dr". What Car?. http://www.whatcar.com/Review/EditionCompare?newOrUsed=New&makeId=9434&modelId=10026&editionId=31419&makeId1=&modelId1=&editionId1=&makeId2=&modelId2=&editionId2=#tabsection3. Retrieved 2010-01-08. 
  110. ^ "Vauxhall Astra Hatchback 2.0 CDTi 160 Elite 5dr". What Car?. http://www.whatcar.com/Review/EditionCompare?newOrUsed=New&makeId=2080&modelId=2199&editionId=31559#tabsection3. Retrieved 2010-07-09. 
  111. ^ "2005 Subaru Legacy 2.0R Technical specifications". http://www.carfolio.com/specifications/models/car/?car=131901. Retrieved 2010-01-08. 
  112. ^ "2008 Subaru Legacy Outback 2.5i Technical specifications". http://www.carfolio.com/specifications/models/car/?car=178321. Retrieved 2010-01-08. 
  113. ^ "Smart Fortwo Cabriolet 1.0 97 Brabus Xclusive (07-09) 2dr". What Car?. http://www.whatcar.com/Review/EditionCompare?newOrUsed=New&makeId=28845&modelId=28846&editionId=28914&makeId1=&modelId1=&editionId1=&makeId2=&modelId2=&editionId2=#tabsection3. Retrieved 2010-01-08. 
  114. ^ "2007 Ford Focus 2.0 Automatic (US) Technical specifications". http://www.carfolio.com/specifications/models/car/?car=176847. Retrieved 2010-01-08. 
  115. ^ "An Assessment of Mass Reduction Opportunities for a 2017–2020 Model Year Vehicle Program". International Council on Clean Transportation. http://www.theicct.org/pubs/Mass_reduction_final_2010.pdf. 
  116. ^ "Toyota HiLux 4×2 Utes 2009". Toyota. http://www.toyota.com.au/TWR/content/static/74843.pdf. Retrieved 2010-01-21. 
  117. ^ "BMW automobiles". Bayerische Motoren Werke AG. http://www.bmw.com/. Retrieved 2010-01-26. 
  118. ^ "Mini Cooper Hatchback 1.6T S John Cooper Works 3dr". What Car?. http://www.whatcar.com/Review/EditionCompare?newOrUsed=New&makeId=29021&modelId=29090&editionId=29144#tabsection3. Retrieved 2010-01-08. 
  119. ^ "2007 Holden WM Caprice". Topspeed. http://www.topspeed.com/cars/holden/2007-holden-wm-caprice-ar13106.html. Retrieved 2010-01-08. 
  120. ^ M1030M1 JP8/Diesel Military Motorcycle, Hayes Diversified Technologies, http://www.dieselmotorcycles.com/PDF/M1030M1_JP8_Diesel_Military_US.pdf, retrieved 2009-02-28 
  121. ^ "2009 Harley-Davidson FLSTF Softail Fat Boy Preview". Topspeed. http://www.topspeed.com/motorcycles/motorcycle-reviews/harley-davidson/2009-harley-davidson-flstf-softail-fat-boy-ar73839.html. Retrieved 2010-01-26. 
  122. ^ "The new BMW 760i; The new BMW 760Li; Contents." (Press release). BMW. March 2009. http://www.bmwblog.com/docs/BMW_760i_760Li.pdf. Retrieved 2010-01-08. 
  123. ^ Edmunds, Dan. "Full Test: 2008 Subaru Impreza WRX STI". edmunds InsideLine. http://www.edmunds.com/insideline/do/Drives/FullTests/articleId=123768. Retrieved 2010-01-08. 
  124. ^ "Vauxhall VXR8 Saloon 6.2 V8 Bathurst 4dr". What Car?. http://www.whatcar.com/Review/EditionCompare?newOrUsed=New&makeId=2080&modelId=4102&editionId=4110#tabsection3. Retrieved 2010-01-08. 
  125. ^ "Roadster Features and Specifications". Tesla Motors, Inc... http://www.teslamotors.com/roadster/specs#specs-2. Retrieved 2011-07-31. 
  126. ^ Vijayenthiran, Viknesh. "Artega GT now on sale". Motor Authority. http://www.motorauthority.com/news/coupes/artega-launches-gt-with-special-edition-model/. Retrieved 2010-01-08. 
  127. ^ "2006 Lotus Exige GT3 Technical specifications". Car Folio. http://www.carfolio.com/specifications/models/car/?car=166628. Retrieved 2010-01-08. 
  128. ^ "Bombardier Dash 8 Q400 Specifications". Bombardier Aerospace. 1997. http://www2.bombardier.com/q400/en/specifications.jsp. Retrieved 2010-07-24. 
  129. ^ a b "2008 Chevrolet Corvette". MSN Autos. http://autos.msn.com/research/vip/spec_Exterior.aspx?year=2008&make=Chevrolet&model=Corvette&trimid=-1. Retrieved 2010-01-08. 
  130. ^ "Press Release - Lamborghini Murciélago LP 670-4 SuperVeloce – the new king of the bulls - is even more powerful, lighter and faster". MotorStars. http://www.motorstars.org/documenti/lamborghini_murcielago_lp_670-4_superveloce_-_en.pdf. Retrieved 2010-03-24. 
  131. ^ "1997 McLaren F1 GT Technical specifications". Car Folio. http://www.carfolio.com/specifications/models/car/?car=77319. Retrieved 2010-01-08. 
  132. ^ "2009 Polaris 800 Assault RMK146 Snowmobile Specifications & Price". Polaris Industries. http://www.polarisindustries.com/en-us/Snowmobiles/2009/DeepSnow/800ASSAULTRMK/Pages/Specifications.aspx. Retrieved 2010-01-19. 
  133. ^ "Ultima GTR 720 (2006 - date)". SupercarWorld. http://www.supercarworld.com/cgi-bin/showgeneral.cgi?362. Retrieved 2010-01-08. 
  134. ^ "The MTT Turbine Superbike". Marine Turbine. http://marineturbine.com/downloads/2008_Turbine_SUPERBIKE_brochure.pdf. Retrieved 2010-01-08. 
  135. ^ "2010 Vyrus 987 Review". Motorcycle.com. http://www.motorcycle.com/manufacturer/2010-vyrus-987-review-89399.html. Retrieved 2010-04-14. 
  136. ^ "Williams FW27". F1 Technical. http://www.f1technical.net/f1db/cars/895. Retrieved 2010-01-12. 
  137. ^ "John Force - Funny Car Legend". Automobile Magazine. http://automobile.automotive.com/70233/0805-john-force-funny-car-legend/index.html. Retrieved 2010-09-10. 
  138. ^ a b "Shuttle Orbiter Endeavour (OV-105)". NASA Kennedy Space Center. http://science.ksc.nasa.gov/shuttle/resources/orbiters/endeavour.html. Retrieved 2010-03-10. 
  139. ^ "F-22 Raptor fact sheet". USAF. March 2009. http://www.af.mil/information/factsheets/factsheet.asp?id=199. Retrieved 23 July 2009. 
  140. ^ "Two Plus One Makes History". NASA. http://www.nasa.gov/missions/shuttle/ET_SRB_prt.htm. Retrieved 2010-03-10. 
  141. ^ "Human Space Flight - Space Shuttle Basics - Solid Rocket Boosters". NASA. http://spaceflight.nasa.gov/shuttle/reference/basics/srb/index.html. Retrieved 2010-03-10. 
  142. ^ "NASA Space Shuttle - Operating the world's most versatile launch system". NASA. 2003-07-18. http://www.nasa.gov/audience/formedia/factsheet/spaceshuttle_factsheet.html. Retrieved 2010-03-10. 

External links