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Three-wheeled car
A three wheeled car, also known as a tricar or tri-car, is an automobile having either one wheel in the front for steering and two at the rear for power, two in the front for steering and one in the rear for power, or any other combination of layouts. 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<ref>Template:Citation/core{{#if:|}}</ref>
History
Early car pioneer Karl Benz developed a number of three-wheeled models.<ref name=Elvis>Template:Citation/core{{#if:|}}</ref> One of these, the Benz Patent Motorwagen,<ref>Template:Citation/core{{#if:|}}</ref> is widely regarded as the first purpose-built automobile,[citation needed]||}} and may be the first petrol car driven on British soil, in 1894.<ref name=Elvis/> In 1896, John Henry Knight showed a tri-car, recognized as the first British-made motorcar, at The Great Exhibition.<ref name=Elvis/> 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.<ref>Template:Citation/core{{#if:|}}</ref>
Strengths and weaknesses
Having one wheel in front and two in the rear for power reduces the cost of the steering mechanism, but greatly decreases stability. However, a configuration of two wheels in the front and one wheel at the back has many strong proponents among automotive designers and enthusiasts. Two advantages are its improved aerodynamics, and that it readily enables small lightweight motorcycle powerplants and rear wheels to be used. This approach was used 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 stability and traction.
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 to a point 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.
The disadvantage of a rear drive, non-tilting three wheel configuration is 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. 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. Electric three-wheelers often lower the center of gravity by placing the heavy battery pack at the base of the vehicle.
Examples
| Name | Country | Years manufactured | Wheel configuration | Comments (see fuller list at Category) |
|---|---|---|---|---|
| Benz Patent Motorwagen | Germany | 1886-93 | 2 rear | |
| 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<ref>Template:Citation/core{{#if:|}}</ref> | England | 1902-12 | 2 front | |
| Humber Tricar<ref>Template:Citation/core{{#if:|}}</ref><ref>Template:Citation/core{{#if:|}}</ref> | England | 1904 | 2 front | |
| Riley Olympia Tricar<ref>Template:Citation/core{{#if:|}}</ref> | England | 1904 | 2 front | illustration |
| Lagonda Tricar<ref>Template:Citation/core{{#if:|}}</ref> | England | 1904-07 | 2 front | total production: 69 cars |
| La Va Bon Train | France | 1904-10 | 2 rear | 50-100 believed built |
| Anglian | England | 1905-07 | ||
| Armadale | England | 1906-07 | ||
| Morgan V-Twin and F-Series | England | 1911-39, 1932-52 | 2 front | |
| 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 |
| Autoette | United States | 1948-70 | 2 rear | |
| Scammell Scarab | England | 1948-67 | 2 rear | |
| Velorex Oskar and other models | Czechoslovakia | 1951-71 | 2 front | Originally with leather bodies |
| Daihatsu Bee | Japan | 1951-? | 2 rear | |
| Iso Isetta | Italy | 1953 | 2 front | |
| Messerschmitt KR175 | Germany | 1953-55 | 2 front | |
| Messerschmitt KR200 | Germany | 1955-64 | 2 front | |
| 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 | |
| Peel P50 | Isle of Man | 1963-64 | 2 front | Smallest production car ever built. |
| Bond 875 | England | 1965-70 | 2 rear | |
| Reliant Robin | England | 1973-81 | 2 rear | |
| HMV Freeway | United States | 1979-82 | 2 front | |
| GM Lean Machine <ref>Template:Citation/core{{#if:|}}</ref><ref>Template:Citation/core{{#if:|}}</ref> | United States | 1980s | 2 rear | Tilt, concept car only, conceived by Frank Winchell, illustration |
| Campagna T-Rex | Quebec, Canada | 1996-present | 2 front | Most likely the fastest (157 mph) most expensive ($50k MSRP) production 3-wheeler |
| 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. [1] |
| ZAP Xebra | United States | 2006-? | 2 rear | electric power |
| Carver | Netherlands | 2007-2009 | 2 rear | Tilt |
| Moonbeam | United States | 2008- | 2 front | 100mpg DIY, fabric-covered car based on parts from 2 Honda 150cc motorscooters. |
| Triac | United States | 2009 | 2 front | Electric |
| 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 | 2010? | 2 front | Electric or Plug-in hybrid, 300 mpgUS |
| Persu Hybrid | United States | 2010? | 2 rear | Tilt, hybrid and electric models, technology licensed from Carver |
Registration
In the U.S. the National Highway Traffic Safety Administration defines and regulates three-wheeled vehicles as motorcycles.<ref name=Related Highway Safety Provisions>Template:Citation/core{{#if:|}}</ref> Licensing requirements vary on a state-by-state basis. In other jurisdictions, such as British Columbia, Canada, a three-wheeled vehicle with an enclosed passenger compartment is considered an automobile.
