Re: Misc. '95 M3 Stuff

[Brian ///M Kennedy <kennedy@xxxxxx>]

George Parker wrote:
> 
>      I am the proud owner of a 95 M3 with the optional LTW wheels.  Unlike
>      the stock wheels, the rear wheels are 8 1/2 x 17 though the tires are
>      still the same 235/40.  Can anyone explain the reason for the extra
>      inch of wheel with no increase in tire size.  Is there a difference in
>      the offset of the wheel?  Does the difference cause any change in the
>      rear tire/suspension setup?  No one at various dealers can explain
>      this to me.

Each 0.5" increase in wheel width results in an effective tire patch width 
increase of 0.2" -- according to Michelin -- up to the max wheel width 
recommended for the tire.

In addition, the wider wheel will put the sidewalls at a larger angle making
them stiffer laterally -- more resistant to rolling over in hard cornering.
OTOH, it makes them less stiff to vertical impacts, which could be the
difference between a bent rim or not the next time you hit a pothole a bit
too fast.


>      Also, when I replace the rear tires, which is soon, I
>      plan to increase width as much as possible.  Can anyone tell me what
>      the max tire size is with and without curling the lip of the wheel
>      well.

Obviously 245/40's will fit.  I have heard 255's will fit; but I've also
heard some minor fender rolling was needed.  As close as my
245's are to rubbing, I can imagine that 255's fitting depends upon the 
tire brand, the specific wheel, and the specific car.

Has anyone experimented with this on multiple cars?  Ben?


Hope that helps,

Brian

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