Talk:Hybrid electric vehicle

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I think this page is biased. It doesn't have any criticism of the technology. For example, a car with a small diesel engine can get better mileage per litre or gallon than hybrid vehicles. Or, a car with a small petrol engine can receive good mileage as well. This article doesn't speak of the problem of having two production lines for making cars, or how to dispose of the batteries when the car is scrapped. The article isn't wrong, but I think it needs work from someone who is an expert on the downsides of the technology.

68.100.194.216 21:48, 8 September 2007 (UTC)

Contents 1 Hybrid car redirect 2 production statistics 3 fuel consumption 4 Transmissionless hybrid? 5 Criticism, analysis 6 PEHV? Overall name? 6.1 Renaming 7 Energy Related Development by Civilizations (category) 8 Heavy reorg work 9 Move locomotives out altogether? 10 Recent edits 11 Production Impact 12 History 13 Hybrids vs. all-electric vehicles 14 Do hybrids really need batteries? 15 Criticism section 16 I'm so confused

[edit] Hybrid car redirect

I think hybrid car should redirect here. Some people apparently think it should redirect to hybrid vehicle (someone reversed my redirect without comment). The hybrid vehicle page has stuff about bicycles and sailboats and other stuff completely irrelevant to cars and this page has a lot of car related stuff (although it does also have train and bus stuff) and I think it's the kind of thing that people searching for hybrid car want to see. Opinions? Plymouths 07:42, 4 January 2007 (UTC)

This reads like a sales pitch from someone who is pro-hybrid, rather than a honest analysis. The "trade-offs" section is very weak in this regard - it mentions a couple of issues and then tries to gloss over them in a postive spin for why folks should buy a hybrid.

Not sure when the above (unsigned) comment was made, but I updated the trade-offs section significantly this weekend. The Toyota Prius page was getting too long, and most of this is relevant to hybrids in general, so I added it here. (You think this is pro-hybrid, read the Prius page). For the record, I own a Prius, but I understand some of its environmental limitations and tried to keep this NPOV. Regarding the first comment, I was expecting all of this under the Hybrid-Electric Vehicle (HEV) page, which is also a redirect. Not sure what is best, but I tentatively agree with Plymouths. Nerfer 05:57, 26 February 2007 (UTC)

I see someone added a note "citation needed", to my discussion on Consumer Reports. Good point, but I don't know how to correct it. Their print issue contains the error, as did their initial online version. The online version was quietly fixed, I don't know that there is any official source admitting this error, but it definitely existed and still exists in the print edition. That's a year ago now, maybe it could just be taken out, although it still comes up every now and again. Nerfer 06:31, 9 March 2007 (UTC)

[edit] production statistics

For the section labelled "production statistics" (I renamed it from just "hybrids" which was totally uninformative) does anyone have a source of where that came from? I inserted that the 2010 and 2015 numbers were projections but I'd like to mention what that projection is based on - is it actual plans by the vehicle manufacturers, some sort of curve-fit extrapolation based on past data, or just wishful thinking of some hybrid advocacy group? I think it would be useful to know. Plymouths 17:49, 23 January 2007 (UTC)

I agree, this needs a source. For one thing, the gas mileage ratings are real low. How about a row for number of hybrids produced, which is much more informative than number of hybrid models compared to number of all car models. Nerfer 17:36, 25 February 2007 (UTC)

Okay, reviewing Wikipedia guidelines I feel comfortable removing it from the article, and copying it here. If the original author wants to keep it and can provide sources (like why is the Honda Insight apparently shown as getting 25 mpg???), then it can be put back in the main article. Nerfer 17:51, 25 February 2007 (UTC)

Production Statistics 

Year	1995	2000	2005	2007	2010(projected)	2015(projected)
Hybrid models in production	0	1	5	10	20	50
Best gas mileage of Hybrid Models in production	22	25	32	42	62	96
Percentage of cars on the road that are Hybrids	0	0	0.01	0.5	2	10
Percentage of car Models in production that are Hybrids	0	0	0	0.01	2	10

Some interesting statistics reported today by the AP: "Consumers bought 254,545 hybrids last year as gasoline prices hit $3 per gallon or more for much of the year. That is up from 199,148 in 2005, according to nationwide auto registration data compiled by R.L. Polk & Co. and released on Monday...Hybrids accounted for about 1.5 percent of U.S. vehicle sales last year, with Toyota's Prius leading the segment with 42.8 percent of registrations, R.L. Polk said. A hybrid version of Toyota's Highlander sport utility vehicle ranked second." Nerfer 16:38, 26 February 2007 (UTC)

[edit] fuel consumption

I fail to see how these cars can have lower fuel consumption, since they need to use more petrol to lug around the batteries and motors. You also need to use electricity (generated in a power station) to charge it up. As shown by "Top Gear", (BBC2), the fuel consumption figures are apparently WORSE than many diesels, and some petrol cars. At low speed, in towns, say, there should be lower emissions, but any other claims appear to be bogus. Some figures and comparisons for consumption maybe? A brief look at the site at the bottom of this article, (www.fueleconomy.gov) appears to show the petrol only variant of one of the cars doing nearly TWICE the mileage of the hybrid. The other hybrids shown all have poor mpg figures compared to many petrol only cars, and certainly diesels.

Peter M.

81.145.240.179 20:26, 4 February 2007 (UTC)

Could you be specific about what you are comparing, where the results are apparently worse in particular? Having lower mileage than diesels is a well understood issue.--Gregalton 20:44, 4 February 2007 (UTC)

From fueleconomy.gov, I tried to get info on all the hybrids I am aware of that have comparable petrol versions to allow a like-to-like comparison.

The results are below. If someone would like to make this into a pretty table and add any that they know of, that would be a good contribution to the article. Any errors or omissions are mine. Whenever possible, I took the least-thirsty petrol engine to compare to the hybrid, and didn't compare horsepower etc. All figures are combined mileage - city/highway differences between hybrid and regular may be different (in particular, the city mileage differential may be larger). Percentage figure is MPG increase for hybrid engine compared to regular.

2007 Highlander 2WD 2.4L manual vs hybrid: 24; 29; 20.8%

2007 Toyota Highlander 4WD 2.4L manual vs hybrid: 22; 29; 31.8%

2007 Toyota Camry manual 2.4L vs hybrid: 28; 39; 39.3%

2007 GMC Sierra C15 2WD 4.3L-six cylinder vs hybrid: 18; 19; 5.6%

2007 Honda Accord (2.4L manual) vs hybrid: 29; 31; 6.9%

2007 Honda Civic 1.8L manual vs hybrid: 33; 50; 51.5%

2007 Lexus GS 430 vs GS450h: 21; 26; 23.8%

2007 Lexus RX 350 2WD vs RX400h: 22; 29; 31.8%

2007 Saturn Vue FWD 2.2L manual vs hybrid: 25; 29; 16%.

So, two cars show very little change: GMC Sierra and Honda Accord. The Sierra is a "light" hybrid if I'm not mistaken. The Accord hybrid is known as having used the hybridization to increase horsepower; the Accord variant with a larger engine has mileage figure of 24, so the hybrid version has a 30% improvement over that version (discussion can ensue which comparison is valid). Aside from these two low-level outliers, and excluding the Civic hybrid as an outlier on the high side, all of the other hybrid versions show an improvement of 16% to 40%.

Clearly there are engineering choices going on here, and variables that have not been controlled for. That said, to say a 25% increase in mileage is conservatively achievable would seem to be reasonable. For city mileage, the hybrids tend to have even larger improvements. Granted, most diesels would probably achieve a similar improvement, but the facts don't support the argument above that there is little improvement in mileage.

I don't see any hybrid with one-half the mileage of its petrol equivalent. That seems to be a mistake.--Gregalton 15:19, 5 February 2007 (UTC)

Just for comparison, I got the similar difference for the 2006 Jetta gasoline/diesel and MB E320/350.

2006 Volkswagen Jetta 2L 6sp manual w/turbocharger (premium gas) vs 1.9L turbodiesel: 27; 38; 40.7%

2006 Volkswagen Jetta 2.5L 5sp manual (regular gas) vs 1.9L turbodiesel: 25; 38; 52%

2007 Mercedes-Benz E350 vs 2007 Mercedes-Benz E320 Bluetec (diesel): 21; 30; 42.9%

So clearly substantial gains to be had from diesel vs petrol. Of course, no reason that a diesel-electric hybrid couldn't be made and combine these gains (cost considerations aside).--Gregalton 18:44, 5 February 2007 (UTC)

You need to remember that diesel contains 25% more energy per gallon than petrol/gasoline (25% more hydrocarbons as well) so that must be remembered when comparing mileage and CO2 emissions. Secondly, some of these hybrid cars have been designed more for performance (extra HP) than for mileage, like the Accord, so you also need to compare the 0-60 mph (0-100 kph) times between hybrids, their gas-only counterparts, and the listed diesel vehicles. 67.184.254.37 17:29, 25 February 2007 (UTC)

Going by the above table (which is consistent with my own research I have changed "often appearing and performing identically to their non-hybrid counterparts while delivering 50% better fuel efficiency" to "40%". The 50% claim is just ridiculous and is only achieved by hybrids with lower power than their counterparts. The civic hybrid for instance has an EPA ~50% higher but that's with the hybrid being significantly less powerful. Also, according to fueleconomy.gov the EPA score for hte hybrid is more overrated than the regular version. Not to mention the fact that people who drive the hybrid almost definitely drive it more conservatively than the average civic drive. So I think 40%.

Wagsbags Feb 7 2007

If there is no reference for the statement then it should be removed. Daniel.Cardenas 06:53, 8 April 2007 (UTC)

Speaking directly to Peter M's questions:

First, a hybrid does not have to be plugged in; the on-board petroleum fueled engine runs a generator or alternator to charge the batteries. Should the petroleum-fueled engine fail, the batteries can be charged from the power network to allow short trips.

Second, a hybrid saves the most energy in stop-and-go city traffic, in which the vehicle starts and stops frequently and travels at a variety of speeds. Also assumed is that the vehicle must be capable of traveling at high (freeway) speeds.

The petroleum-only vehicle has an efficiency advantage when the engine runs at the constant throttle setting and load at which its engine runs at peak efficiency. Typically this would be constant speed on a level freeway. This is why hybrid vehicles are not being considered to replace diesel interstate trucks, which spend much of their time on the freeway at a constant speed and thus mostly run near peak efficiency.

In a petroleum-only vehicle, the engine must be large enough to provide the required peak power and generally must run all the time when the vehicle is being driven. The large engine is heavy and requires a large cooling system which is also heavy. It takes power to keep the engine turning, due to friction and air-pumping losses. Air-pumping losses are the energy spent sucking air into the intake, through internal passages, and pushing it out the exhaust, like an air compressor. Air-pumping losses vary with throttle setting and engine speed.

In a hybrid vehicle, the engine is smaller and does not have to run all the time. This smaller engine is lighter and can use a smaller and lighter cooling system, which partially offsets the weight of the other components. It takes less power to keep the engine turning, since it is both smaller and not always running. Thus the friction and air-pumping losses are much lower.

In a petroleum-only vehicle, engine efficiency changes drastically according to the throttle setting and output power. The best efficiency is found at some particular engine speed / throttle / load combination, and the efficiency drops off away from that combination. E.g. when you take your foot off the gas pedal and brake toward a stop, the engine is still using fuel but not doing any useful work. In fact the engine can perform "engine braking", providing negative power output, in which the friction and air-pumping losses allow the engine to absorb the vehicles' kinetic energy and slow it. This absorbed energy is dissipated as heat and wasted.

In a hybrid vehicle, the engine's operation is mostly independent of the throttle setting, and can be alternately run at its best efficiency point or shut off. The electric motor efficiently provides a variable amount of power for acceleration. When regenerative braking is used, the electric motor can also provide deceleration by acting as a generator, putting the energy into storage for later use instead of wasting it as heat. Needexercise 05:28, 10 May 2007 (UTC)

[edit] Transmissionless hybrid?

There isn't much material on the Internet about transmissionless hybrids. I'm thinking an ICE with a wide torque band could drive rear wheels through a differential but without a transmission at highway speeds, let's say 35mph @ 1,500 rpm up to 90 mpg @ 4,000 rpm. Electric motors could be used on front wheels for low-speed driving, acceleration, hill climbing, reverse, and regenerative braking. The ICE could also drive a generator as charging needs and power demands dictated.

The supplemental wheel motors ought to be substantially cheaper, more reliable and lighter than automatic transmissions typically used in hybrids, and they would render a transmission and front wheel brakes superfluous. —The preceding unsigned comment was added by 76.80.26.121 (talk) 23:35, 7 February 2007 (UTC).

There is nothing to be gained by forcing an engine to work across the RPM and MPH ranges you note there. All you will do is have the engine spend needless amounts of time outside its optimal RPM range. While yes the engine could operate across that range in one gear, for much of it it would not be producing optimal power, and would be running at far less than optimal efficiency. This would make the car sluggish, and reduce its fuel efficiency. The RPM/MPH range you note is about equivalent to 5th gear in a 5-spd manual vehicle. If you have access to a car with a 5-spd, try driving it around at the speed range you noted, keeping the transmission in 5th gear. You'll quickly see that below 55-60 the car will be extremely slow, and unresponsive. And since the car is operating outside its optimal RPM range the fuel economy will suffer dramatically.

If you take a closer look at the design of the Prius, (and several smaller non-hybrid cars) you'll see a movement to Continuously variable transmissions . These transmission are constantly adjusting the relative gearing to keep the engine in the optimal range as much as possible. These transmissions optimize power and/or efficiency output of the engine.

Lastly, even if the issues with running an engine were not there, there is no way your design would be cheaper than using a transmission. A normal car just needs the engine, transmission and differential. Your design requires an engine, differential, electric motors (multiple), battery pack, a clutch to disengage the engine when the motors are running, multiple clutches to disengage the motors while the engine is running, wiring and electronics to control the electric motors, the regenerative braking and switch between the engine and motors. This is far more complex, which would end up making it more expensive to produce and maintain than the standard system. Transmission and front brakes are known technology and can be produced (relatively) cheaply, at least when compared to the all new technology of much greater complexity that you are proposing. Improbcat 16:09, 23 February 2007 (UTC)

[edit] Criticism, analysis

The content under CNW Marketing reports contains considerable analysis and original research - I've copied it (with credit) to Appropedia: Hybrid vehicles, as Appropedia (the sustainability wiki) happily accepts such material.

I'll leave it to someone else to trim unsuitable material from the Wikipedia article, and perhaps reference the Appropedia article. --Chriswaterguy talk 04:32, 26 March 2007 (UTC)

Diesel-electric HEVs use a diesel engine for power generation. Diesels have advantages when delivering constant power for long periods of time, suffering less wear while operating at higher efficiency. The diesel engine's high torque, combined with hybrid technology, may offer substantially improved mileage. Most diesel vehicles can use 100% pure biofuels (biodiesel), so they can use but do not need petroleum at all for fuel (although mixes of biofuel and petroleum are more common, and petroleum may be needed for lubrication). If diesel-electric HEVs were in use, this benefit would likely also apply. Diesel-

I feel compelled to comment on this. "Most diesel vehicles can use 100% pure biofuels (biodiesel)" This is true but only anecdotally as I know of no comprehensive study concluding that use of 100% biodiesel is a drop-in substitute for regular diesel. I have about 30k miles of 100% biodiesel on by VW with no problems but I think that it is important that readers understand that the user must be aware that the risks and the effects of long-term use of 100% bio at this point is unknown. In short: "Most diesel vehicles can use 100% pure biofuels (biodiesel)" and "do not need petroleum at all for fuel" are not only used without citation but to the best of my knowledge, there is no such broadly accepted study to cite. Tegtmeye 13:18, 22 August 2007 (UTC)

[edit] PEHV? Overall name?

This article has been renamed from petroleum electric hybrid vehicle to hybrid electric vehicle as the result of a move request. --Stemonitis 06:53, 14 May 2007 (UTC)

[edit] Energy Related Development by Civilizations (category)

I don't like it. Just makes the article longer and more complicated. What do you think? Daniel.Cardenas 19:27, 12 May 2007 (UTC)

[edit] Heavy reorg work

Right, I'm done for now. Still a ton of work to do, but the article has some semblance of coherence now. Chris Cunningham 14:19, 13 June 2007 (UTC)

[edit] Move locomotives out altogether?

Hybrid locomotives are really pretty different to hybrid cars. Should we just split this out entirely and leave it to a seealso? It's allow us to combine the fuel-types and vehicle-types sections more neatly. Chris Cunningham 16:37, 13 June 2007 (UTC)

[edit] Recent edits

I'm going to roll these back:

1. The intro section should of course compare hybrids to all-electrics, but doing so in a positive way is probably a better idea (to show why people use hybrids and not all-electrics). I'm editing this accordingly.
2. We're a little long in the tooth for section-stubs at the point. If the legislative section expands enough by itself to warrant these sections and subsections it should be rolled into its own article and linked. This kind of listy material of current legislature is important for some, I suppose, but not so important to this article that it needs a framework like this in place.
3. In my mind, legislature includes incentives. So there's no need to expand the section title.

Chris Cunningham 07:36, 14 June 2007 (UTC)

[edit] Production Impact

production costs,what is the environmental impact of creating a nickel hydride battery?

• I think this information is essential to the article because the end use of the HEV is to reduce humanity's detrimental environmental impact, however, if HEV production is more hazardous to the environment than the production or end use of its predecessors, then the HEV completely negates justification for its existence.

63.103.4.4 16:13, 18 June 2007 (UTC)

[edit] History

I corrected the history section. The Mixte was Porsche's series-hybrid, and was built in 1901. It was only used for racing and never sold to the public. The "System Lohner-Porsche" was a pure-electric vehicle without a gasoline motor. Improbcat 15:32, 15 June 2007 (UTC)

[edit] Hybrids vs. all-electric vehicles

This section was removed [7], apparently it needs more/better references so perhaps it can be fixed here and then replaced. Not sure how much of this section is useful, perhaps some of the references. It may be worthwhile to point out some of the differences between a gas fueled hybrid and an electric fueled BEV, perhaps this can be done elsewhere in the article... --D0li0 11:31, 16 June 2007 (UTC)

Battery powered all-electric cars (BEVs) are more popular in Europe than in the U.S. Most European electric vehicles are purchased from manufacturers, while due to unavailability of manufactured vehicles, most U.S. vehicles are owner-built conversions of older conventional vehicles. The major U.S. automobile manufacturers argue that customer demand for pure electric cars is small. In addition, the long suburban commutes common in the U.S. make range an important criterion for electric vehicle design. However, if advances in battery technology allow increased range at comparable cost to gasoline-powered vehicles, manufacturers will likely mass-market electric vehicles. The relative cost of gasoline to an equivalent amount of electrical energy will also be a critical factor in the electric vehicle market.

Another relevant factor is the ultimate source of power for the electric vehicles. In areas where older coal-fired generators are the source of electrical power, a pure electric vehicle will be responsible for more of some types of pollution — namely sulfates and particulates — than a hybrid vehicle, while less of other types of pollution, such as carbon monoxide and nitrogen oxide emissions.^[1] Whether greenhouse gas emissions will be lower in such a case is still under debate.^[2][3] In any event, the local pollution effects would be lessened by a fleet of electric cars, because the sources of the pollution would be outside of urban areas.

In areas that sources from renewable energy (solar energy), electric vehicles are the cleaner option.

A possible advantage of the hybrid vehicle is in not requiring any upgrades to the electric power transmission grid. Since it can't be scaled larger and smaller at will, the grid is sized so as to carry almost the maximum load (i.e. summer air conditioning) with only occasional failures, and thus has much of its capacity idle most of the time. For the electric utilities, it would be advantageous to utilize that excess capacity and thereby generate a greater revenue for their fixed investment, by selling power to consumers to recharge their vehicles. However, this vision very pointedly does not allow for recharging of vehicles during peak usage times; to do so would require substantial upgrades to the capacity of the grid, and again leave the utilities with excess capacity most of the time. On the other hand, to require consumers to refrain from recharging their vehicles during certain times may not be an easy idea to sell to them.

For now, car manufacturers are focusing on fuel cell-based cars and hybrids. Fuel cell vehicles are being developed in a long-term research environment, rather than with expectations of production at any definite time.

---

[edit] Do hybrids really need batteries?

hybrid electric vehicle (HEV) is a vehicle which combines a conventional propulsion system with an on-board rechargeable energy storage system (RESS)

At the very least, we need a citation. The word "hybrid" makes me think that any propulsion system that isn't either purely combustion or purely electric, but uses both, would be a hybrid electric vehicle. 171.71.37.103 00:41, 18 July 2007 (UTC)

[edit] Criticism section

Why is there no section outlining popular criticism of hevs, both automotive and environmental in nature? --NEMT 20:51, 31 July 2007 (UTC)

[edit] I'm so confused

Back in the spring of '74, I took a transportation engineering course (civil eng) and the professor covered hybrids in a lot of detail. Parallel, series, regenerative braking, gas/diesel/alt fuels, Otto/Diesel/Stirling and other cycle engines, auto/CVT/alternative transmissions, battery and flywheel storage systems etc. However, almost everything in this article suggests those ideas came up later in time - in the late '70s or in the '80s. I associate most hybrid ideas as being from the '60s. Have folks been focussing on the more famous engineers/developments or have I been living in a timewarp? :) --Michael Daly 21:09, 19 October 2007 (UTC)