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[rzm3]

So, I am considering track tires for my M3. A lot of people here mentioned the Cups, so I did a little research.

The Concept M3 came with 19" CSL + Cups:

Front: 235/35/19
Rear: 265/30/19

However, the OE 19s come with:

Front: 245/35/19
Rear: 265/35/19

So, using the tire diameter calculator, I computed the difference between OE and Cups:

Front: -4.891%
Rear: -4.13%

So, my question is: is such a big difference in diameter still going to be ok on the M3? Tire rack recommends deviating within 3% of the OE diameter.

Moreover, for 19" wheels, Cups only come in:

235/35/19
265/30/19
305/30/19
325/30/19

Thus, the 235 front and 265 rear seem to be the only possible choices for Cups to be used on the M3. There is a big difference in diameter on possible 18" wheels+tires also.

Advice? Comments?

[Gearhead999s]

I have the same dilema and I have settled on going with an 18" setup with the New Toyo R888 for trackday & Solo 1 use.

http://www.toyo.com/docs/tires/tires...category=sport

I will be using 255/35-18's which are 25.1" high for the fronts
265/35-18 25.4" rears

At least this combination will retain some of the stagger of the stock setup and will lower the tall stock gearing by a little bit.I am still checking on the availability of the tires as Toyo in Canada has never been great at supplying "funny" sizes in the performance tire line.Once I know I will start working on a wheel setup.
Failing this I will probally just run 245/40 - 18's all the way round and least I will be able to get the back around to come around!I want to run the Toyo's as they support Grassroot Motorsports big time in our region.

[GregW / Oregon]

Originally Posted by rldzhao

So, I am considering track tires for my M3. A lot of people here mentioned the Cups, so I did a little research.

The Concept M3 came with 19" CSL + Cups:

Front: 235/35/19
Rear: 265/30/19

However, the OE 19s come with:

Front: 245/35/19
Rear: 265/35/19

....

Moreover, for 19" wheels, Cups only come in:

235/35/19
265/30/19
305/30/19
325/30/19

Thus, the 235 front and 265 rear seem to be the only possible choices for Cups to be used on the M3. There is a big difference in diameter on possible 18" wheels+tires also.

Advice? Comments?

The stock 245/35 & 265/35 R 19 Sport Cup+ are offered. The difference is in the +. In fact, they are the only 19" sizes offered, and were likely developed for the M3. Probably were not available when the Concept was released, and probably not available in the US yet. It'd be worth waiting for the right size. See the chart here:

http://www.michelin.co.uk/uk/front/a...20080128103043

[rzm3]

ic. they are listed as XL on the US web site. thanks for the info.

http://www.michelinman.com/tires/ult...lot-sport-cup/

[sayemthree]

ideal would be 265 all around. 4% change in diameter should be fine for the track.

[rzm3]

anyone know where i can get CSL wheels with M3 fitment? (i know i can use spacers but trying to avoid them)