I wonder whether the P34 died too soon. Basically, I'm wondering whether the additional pair of wheels could have conferred the car any advantages that, if solved, would have given it an advantage over 4-wheeled F1 cars.

6-wheeled F1 cars have had a very brief existence but what if R&D continued? Would it have overtaken the 4-wheeled F1 cars?

  • $\begingroup$ Link-only questions are bad, just like link-only answers. Include the pertinent parts of your question HERE. Closing. $\endgroup$ – Olin Lathrop Jul 19 '16 at 11:08

The complication here is that the simple relationship between wight (or downforce assisted equivalent) coefficient of friction and traction is only true up to a point and in performance tyre that point is where the thermal and mechanical loads on a tyre start to change its mechanical properties.

Performance tyres are generally designed to work best with a small amount of slip angle ie just at the point where static friction transitions to sliding friction so in an F1 context the contact patch of the tyre very much does make a difference. In this context the 'grip' is effectively the maximum load a tyre can tolerate before it transitions from static (rolling) friction) to sliding friction.

This is not so much about the 'classical' theory of static friction as that ability of the tyre compound to deal with the amount of energy being put into it.

The 6 wheeled car was not so much about the fact that 4 drive wheels are better than two but a clever exploitation of the regulations which limited rear tyre size but neglected to specify that you could only have two axles, something witch was very quickly changed.

Note also that the 2017 F1 regulations increase the width of the tyres for the explicit reason of increasing performance.

In summary while a larger tyre contact patch does not increase grip/traction in general it very much does increase the upper limit of grip where the limiting factor is the breakdown of the tyre compound.


The premise that increasing the area of the contact between the tires and the road somehow increases traction is fundamentally flawed.

As any first-year physics student can tell you, the available frictional force is proportional only to the coefficient of friction between the two materials and the total force holding them together — the area of the contact drops out of the equation.

The only advantages to adding more wheels would have to be due to secondary effects, such as being better able to maintain contact in dynamic situations such as driving on a rough surface. And any such advantages would have to be balanced against the disadvantages associated with the extra complexity, power losses and weight.

  • $\begingroup$ Are those the only issues? What about added rotational inertia due to the extra pair of tires? $\endgroup$ – Aidan Rocke Jul 17 '16 at 12:16
  • $\begingroup$ What about it? It would store some energy, but I don't see how that applies to your question. $\endgroup$ – Dave Tweed Jul 17 '16 at 12:18
  • $\begingroup$ The extra rotational inertia would require extra mechanical energy which would actually make the car less efficient. $\endgroup$ – Aidan Rocke Jul 17 '16 at 12:21
  • 1
    $\begingroup$ OK, so that't the sort of thing I was talking about when I said "disadvantages associated with ... power losses and weight." I wasn't trying to enumerate every possible example of such effects. $\endgroup$ – Dave Tweed Jul 17 '16 at 12:25
  • $\begingroup$ Point taken. I actually think there might have been design failures but the engineers that worked on it were definitely brilliant. It would be interesting to hear what they actually have to say on the matter. $\endgroup$ – Aidan Rocke Jul 17 '16 at 12:50

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