This is a sketch for a simple three-wheel car optimised for city commuting. There is a strong emphasis on safety and simplicity as opposed to optimising the car to the sports market.

This is a sketch for a simple three-wheel car optimised for city commuting. There is a strong emphasis on safety and simplicity as opposed to optimising the car to the sports market.

The car is based on the layout of the Humber Kindred Spirit three-wheel car of the 1970s. Some changes have been made in the there is now an enclosed canopy to keep the rain and wind out. The seating position has been raised to increase driver comfort and to aid in the visibility of the vehicle in regards to other traffic. Because the height of the car has been raised as opposed to the original Kindred Spirit, the center of gravity has been raised slightly as well. To give comparable stability the wheel track has been widened to compensate for this. An open wheel layout allows for a widening of wheel track for only a very modest weight penalty.

One prominent feature of the car is that there are very wide side impact protection bulges. This is in response to my reading that a full 35% of fatalities in car crashes are the result of side impact collisions. Note that side impact collisions no doubt make up much less than 35% of collisions, but the thin door provides minimal protection as opposed to frontally. Thus if someone is unlucky enough to be involved in a side impact accident their chances are not as good. In my opinion if the layout of a car is one seat behind the other then it is prudent to add such wide bulges to improve safety whilst noting that they do not affect the overall width of the car and the weight penalty involved is minimal die to the use of low density foam for side protection.

Entrance to the car is via a hinged cockpit on only one side. This is not super comfortable, however it reduces weight and allows for structural members to run lengthwise at waist height thus giving the car a stronger more rigid structure and good protection from side impact. (No doors to weaken these structural beams)

A big advantage of a 3-wheeled car is that it uses much less fuel. This is primarily due to its lower weight. Weight can be reduced by having only 2 seats not 4, by having 3 wheels not 4, by having one door (hatch), eliminating the differential, making the structure smaller. It is hoped that the vehicle should be fairly stable, hopefully comparable to common 4 cylinder cars such as Honda Jazz, Toyota Yaris etc. I feel that the 2 wheels forward, one back is a more stable layout than the one wheel forward, 2 wheels back as per the Reliant car.

Some anecdotal evidence to support this can be found in the good reputation of the Morgan 3 wheeler. Some other 3 wheelers that appear impressive, in no order are Aptera, Grinnal Scorpion, Lomax, Blackjack Zero, T-Rex, Tri magnum