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      04-11-2021, 04:08 PM   #59
Obioban
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Drives: 05 M3, 04 M3iT , 01 M5, 17 i3
Join Date: Apr 2008
Location: West Chester, PA

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Quote:
Originally Posted by stressdoc View Post
We have been drifting a bit off topic here... but a few more thoughts. 'Grip' depends on friction between tire rubber and road. More tire contact patch can increase grip up to a point - e.g., wider tires slide more easily on ice. All things being equal, if tires on the outer side of a curve have more grip, the car will lean more, higher g.

And yes, we are comparing recent (F80) M3s. Discussing which M3 had best steering feel and handling deserves a pitcher of really good cold beer. I would love to have a pristine E36. I still miss my 2002tii...
Makes sense-- F8X is the only M3/4 with garbage steering (well, probably the new one, too), as the only EPS version-- and it's heavier than an i8, with wider tires (both with for steering feel). So, I think that's accurate-- the i8 has marginally better steering feel than the F8X M3/4, and WAY worse steering feel than any M3 prior to it.

That said, if you look at the physics equation for the force of fiction:
F=μN
(verify here: https://sciencing.com/calculate-forc...n-6454395.html )

Translated:
(Force of friction) = (coefficient of friction) X (normal force)

Further translated:
(Tire grip) = (tire compound) x (weight of car)

Obviously a heavier car also places more load on the car under cornering, so making a car heavier doesn't make it grip better. But, that is why downforce works so well-- increasing the grip without increasing the cornering load.

Wider tires do worse on snow because they make it easer to effectively hydroplane (on the snow)-- the wider (but shorter) contact patch means more snow has to be displaced or driven on top of.
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