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View Full Version : Another boring tyre size question.


BM-Bob
04-20-2008, 12:28 AM
Sorry to ask the same old question but I couldn't find an easy answer via the search function.

I own a '94 Euro M3 that was delivered in Australia. The original tyre was 235/40/17 front and rear. The fronts are 7.5" and the rears are 8.5" wide. I could never understand why BMW ran the same size tyres when there was 1" difference in the widths?
OK.... I now need new tyres and had my heart set on the Bridgestone Adrenalin. The only problem is they don't make them in a 235/40/17. I considered running 225/45/17's on the front and 255/40/17's on the rear. The rolling diameter is pretty much identical, but I hate the thought of running a narrower tyre than the factory original. I've read good write-ups on the Goodyear GS-D3s which are available in the 235/40/17 size.

So... do I just bite the bullet and replicate exactly what the tyre placard says and know my insurance company won't hassle me if that unfortunate day arrives or put slightly larger rears such as 245's or 255? Or stick to the Adrenalins and run the narrower front combinations? I'm really uncomfortable with this so if anyone else has been through this dilemma I'd be grateful if you could give me some advice please.

Many Thanks.....

Bob.

fun2drive
04-20-2008, 04:30 PM
The only reason BMW went to the smaller front tire is to induce more understeer given the the legal system in the US I can understand that.
I would run whatever tire you like and I don't think your will see much difference really. I have both set ups and all I really see is the ability to rotate my 235's front to back....

BM-Bob
04-20-2008, 04:36 PM
The only reason BMW went to the smaller front tire is to induce more understeer given the the legal system in the US I can understand that.
I would run whatever tire you like and I don't think your will see much difference really. I have both set ups and all I really see is the ability to rotate my 235's front to back....

Thanks for that...........

Are you saying you run 235/40/17's all round?

I'm thinking of running 235/40/17 on the front and 245/40/17's on the rear. Is that a common arrangement?
Thanks again.

Bob.

Mr.///Matt
04-21-2008, 07:38 AM
WOW.... the original should have been 225/40/17 in the front and 245/40-45/17....