ClubLexus - Lexus Forum Discussion - A 6 wheeled Coupe, WHY?

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1976 Tyrrell P-34 - Photo courtesy Dennis David & Family

As demonstrated by the Tyrrell P34 F1 car, those four "front" wheels lead to a myriad of troubles. Even the supposed advantages work against you. The advantage of putting a similar contact patch on the ground with the smaller (10 inch!), more aero-efficient tires falls apart under heavy braking. Smaller brake discs require a LOT of tuning to achieve parity with the rears - the P34 actually used three master cylinders to achieve this. Brake balance is yet another snare awaiting the unwary. If the fronts lock up first, your wheelbase is "shortened" instantly, and catching the tail coming around requires a great deal of skill and no small amount of luck. Should the #2 axle lock up first, the wheelbase is instantly "stretched" and steering inputs slow, requiring more lock, creating understeer and eventual breakaway.

There's another consideration: the combined contact patches of the front two rows are huge, compared to that of the third. Specific loading of the tandem axles is low, as the load is split between four wheels rather than two. What looks like a lot of rubber doesn't have a lot of downforce - or grip. Tyrrell figured that out pretty quickly, and the aero-advantage was quickly absorbed by the comparatively squirrely handling under heavy braking.

But there was yet another problem with the P34 caused by 1976's tire technology. The tiny front tires were bias-ply, as there was not a lot of experience with radials in 1976 that could survive the racing environment at the high rotational speeds the little wheels would achieve on the longer courses. Although the Tyrrell-Ford achieved a one-two finish in the Swedish GP that year, driven by Jody Scheckter and teammate Patrick Depailler, the team abandoned the 6-wheeler after the '77 season.

It did get a lot of attention, and that's obviously the point of the Covini C6W. In the stratospheric world of supercars, this one stands out simply for having two extra wheels. The disadvantages of those tandem fronts are somewhat minimized by at least being a bit closer to the size of the rear wheels, but the aero-advantage goes away too. You are left with a quirky, not to say freakish-looking automobile that probably doesn't handle as well as her more conventional rivals. Driving an art car for the price of an exotic seems a poor investment, but someone with the disposable income of a third-world nation and little sense will probably buy it. :dunno:

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Covini C6W - Photo courtesy jalopnik