A three wheeled car, also known as a tricar or tri-car, is a powered vehicle, legally classed as either an automobile or motorcycle, that has one wheel in the front and two at the rear, or two in the front and one in the rear. Due to its handling superiority, an increasingly popular form is the front-steering "tadpole" or "reverse trike" sometimes with front drive but usually with rear drive. A variant on the 'one at the front' layout was the Scott Sociable, which resembled a four-wheeler with a front wheel missing.[1]
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Early car pioneer Karl Benz developed a number of three-wheeled models.[2] One of these, the Benz Patent Motorwagen,[3] is widely regarded as the first purpose-built automobile. It was built in 1885.
In 1896, John Henry Knight showed a tri-car at The Great Exhibition.[2]
In 1897, Edward Butler (inventor) made the Butler Petrol Cycle, another three-wheeled car.
A Conti 6 hp Tri-car competed in (but did not complete) a 1907 Peking-to-Paris race sponsored by a French newspaper, Le Matin.[4]
A configuration of two wheels in the front and one wheel at the back presents two advantages : it has improved aerodynamics, and that it readily enables small lightweight motorcycle powerplant and rear wheel to be used. This approach was used by Messerschmitt kr200 and by the BMW Isetta. Alternatively, a more conventional front-engine, front wheel drive layout as is common in four-wheeled cars can be used, with subsequent advantages for transversal stability (further front location of CG) and traction (two driven wheels instead of one). For the lowest wind resistance (which increases fuel efficiency), a teardrop shape is desirable. A tear drop is wide and round at the front, tapering at the back. The three wheel configuration allows the two front wheels to create the wide round surface of the vehicle. The single rear wheel allows the vehicle to taper at the back. This approach is used by the Aptera 2 Series. It is also used by Myers Motors for both its single passenger NmG and upcoming 2-passenger Duo.
Having one wheel in front and two in the rear for power reduces the cost of the steering mechanism, but greatly decreases lateral stability when cornering while braking.
The disadvantage of a three wheel configuration is lateral instability - the car will tip over in a turn before it will slide, unless the centre of mass is much closer to the ground or the wheelbase is much wider than a similar four wheel vehicle. Electric three-wheelers often lower the center of gravity by placing the heavy battery pack at the base of the vehicle.
To improve stability some three wheelers are designed as tilting three wheelers so that they lean while cornering like a motorcyclist would do. The tilt may be controlled manually or by computer.
For a more complete list, see Category:Three-wheeled motor vehicles. Two Front Wheels models :
| Name | Country | Years manufactured | Wheel configuration | Comments |
|---|---|---|---|---|
| Léon Bollée Voiturette | France | 1895-? | 2 front | |
| Egg | Switzerland | 1896-99 | ||
| Advance 6 hp air-cooled Tri Car and 9 hp water-cooled Tri Car[5] | England | 1902-12 | 2 front | |
| Humber Tricar[6][7] | England | 1904 | 2 front | |
| Riley Olympia Tricar[8] | England | 1904 | 2 front | [9] |
| Lagonda Tricar[10] | England | 1904-07 | 2 front | total production: 69 cars |
| Anglian | England | 1905-07 | ||
| Armadale | England | 1906-07 | ||
| Morgan V-Twin and F-Series | England | 1911-39, 1932-52 | 2 front | Morgan Super Sports 2-Seater 1937 |
| American Tri-Car | United States | 1912 | ||
| Birmingham Small Arms Company Three Wheeler | England | 1929-36 | 2 front | 1100cc engine; image and description |
| Zaschka | Germany | 1929 | 2 front | Folding three wheeler: Zaschka Three-wheeler 1929 |
| Dymaxion car | United States | 1933 | 2 front | Concept car designed by Buckminster Fuller |
| Mathis VEL 333 | France | 1946 | 2 front | 3 seats, flat-twin front engine, aluminium body, production less than 10 units |
| Velorex Oskar and other models | Czechoslovakia | 1951-71 | 2 front | Originally with leather bodies |
| Iso Isetta | Italy | 1953 | 2 front | |
| Messerschmitt KR175 | Germany | 1953-55 | 2 front | |
| Messerschmitt KR200 | Germany | 1955-64 | 2 front | |
| Peel P50 | Isle of Man | 1963-64 | 2 front | Smallest production car ever built. |
| HMV Freeway | United States | 1979-82 | 2 front | |
| Campagna T-Rex | Canada | 1996-present | 2 front | Most likely the fastest (157 mph) most expensive ($50k MSRP) production 3-wheeler |
| Malone Car Company Skunk SS|TAZR | United Kingdom | 1999-present | 2 front | High power internal combustion and pure electric versions released November 2010 [1] |
| Cree SAM | Switzerland | 2001 | 2 front | Electric, only 80 produced |
| ScootCoupe | United States | 2004- | 2 front | Smallest production car currently, requiring no license to operate due to its moped drive-train |
| Myers Motors NmG ("No more Gas") | United States | 2006- | 2 front | Single occupant all-electric plug-in: 75mph, 50-60 mile range, lithium batteries. Developed from Corbin Sparrow. The 2-passenger model, the Duo, is scheduled for release in 2010. [2] |
| Moonbeam | United States | 2008- | 2 front | 100mpg DIY, fabric-covered car based on parts from 2 Honda 150cc motorscooters. |
| Triac | United States | 2009-2011 | 2 front | Electric, never entered production |
| XR-3 Hybrid | United States | Plans-2008, Kit-2009 | 2 front | Front 3 cylinder diesel (125 mpg), rear electric 40 mile range -(220 mpg when used as a hybrid) |
| Aptera 2e | United States | 2 front | Electric or Plug-in hybrid, 300 mpg-US (0.78 L/100 km) |
Two Rear Wheels models :
| Name | Country | Years manufactured | Wheel configuration | Comments |
|---|---|---|---|---|
| Benz Patent Motorwagen | Germany | 1886-93 | 2 rear | |
| La Va Bon Train | France | 1904-10 | 2 rear | 50-100 believed built |
| Autoette | United States | 1948-70 | 2 rear | |
| Scammell Scarab | England | 1948-67 | 2 rear | |
| Daihatsu Bee | Japan | 1951-? | 2 rear | |
| Daihatsu Midget | Japan | 1957-72 | 2 rear | |
| Mazda T-2000 | Japan | 1957-74 | 2 rear | |
| Mazda K360 | Japan | 1959-69 | 2 rear | |
| Mazda T600 | Japan | 1959-71 | 2 rear | |
| Electra-King | United States | 1964?-1980s? | 2 rear | Two-seater electric car manufactured by B & Z Electric Car Company; advertising brochure |
| Bond 875 | England | 1965-70 | 2 rear | |
| Reliant Robin | England | 1973-81, 1989-2002 | 2 rear | |
| GM Lean Machine [11][12] | United States | 1980s | 2 rear | Tilt, concept car only, conceived by Frank Winchell, illustration |
| Twike | Germany | 1995-present | 2 rear | Human-electric hybrid |
| ZAP Xebra | United States | 2006-2009 | 2 rear | electric power |
| Carver | Netherlands | 2007-2009 | 2 rear | Tilt |
In the U.S. the National Highway Traffic Safety Administration defines and regulates three-wheeled vehicles as motorcycles.[13] Licensing requirements vary on a state-by-state basis. In other jurisdictions, such as British Columbia, Canada, and Connecticut, a three-wheeled vehicle with an enclosed passenger compartment or partially enclosed seat is considered an automobile.
