BMW E90 msport tyre sizes

cozzie55

Hi

I have an E90 BMW 3 Series msport and i need to get new rear tyres for it. Currently the car has tyre sizes 255/40/17/94w on the back and 225/45/17/94w on the front.

I've gone to three different garages down the country and all of them have told me that they never fit 255/40/17s to a car. These garages are all fairly large so i doubt they are messing with me. All three garages have told me they can order 255/40/17 from the UK but that they will cost me in the region of €250 each. The other option they have given me is to put 255/45/17s on the car which will cost me €130 each. The prices given are for the same type of bridgestone runflat.

Can anyone see any issue with changing to 255/45/17 on the car?

Ferris

176eur on Oponeo - http://www.oponeo.ie/details-tyre/bridgestone-re050-a1-255-40-r17-94-w-run-on-flat#78193113

255/45/17 seem to be much dearer on Oponeo.

As standard your fronts are -0.24% in diameter - a very small difference

With the 45 section rears your difference would be -4.26% and the tyre size calculator on Oponeo is saying that that is too much.

Best case it would make your speedo under read, worst it could give you issues with traction control.

cozzie55

Ferris wrote: »

176eur on Oponeo - http://www.oponeo.ie/details-tyre/bridgestone-re050-a1-255-40-r17-94-w-run-on-flat#78193113

255/45/17 seem to be much dearer on Oponeo.

As standard your fronts are -0.24% in diameter - a very small difference

With the 45 section rears your difference would be -4.26% and the tyre size calculator on Oponeo is saying that that is too much.

Best case it would make your speedo under read, worst it could give you issues with traction control.

How did you work out the percentages?
On oponeo i can't see options for m sport E90's which have are bigger than the standard E90.

bazz26

You don't search by specific car, you search by tyre size.

Are your rims OEM or after market OP? Is it possible that the previous owner stuck a set of odball sized after market rims and tyres on?

I had an E90 M Sport but it was fitted with 225/40/r18 (front) and 255/35/r18 on the back but they were factory upgraded wheels.

Edit: According to this similar thread your size is standard OEM on the M Sport:

http://www.boards.ie/vbulletin/showthread.php?p=72003967

cozzie55

bazz26 wrote: »

You don't search by specific car, you search by tyre size.

Are your rims OEM or after market OP? Is it possible that the previous owner stuck a set of odball sized after market rims and tyres on?

I had an E90 M Sport but it was fitted with 225/40/r18 (front) and 255/35/r18 on the back but they were factory upgraded wheels.

Edit: According to this similar thread your size is standard OEM on the M Sport:
http://www.boards.ie/vbulletin/showthread.php?p=72003967

The alloys are the standard factory fitted 17inch ones. I've read a few posts from people who seem to have the same tyre sizes as mine fitted from the factory. The garage are only questioning the aspect ratio of 40 on the wheels currently on the car and recommend that i change to the 255/45/17 wheels as a result

bazz26

I'd stick to OEM size. These are worth looking at:

Front:
http://www.oponeo.ie/details-tyre/bridgestone-re050-a1-225-45-r17-91-v-run-on-flat---fr#80638661

Rear:
http://www.oponeo.ie/details-tyre/bridgestone-re050-a1-255-40-r17-94-v-run-on-flat-#80628910

wandererz

Hopefully you will get the tire size issue sorted out.

However, are you sure you want run-flats?

I opted for 17" non-runflat Bridgestones this time and am glad i did. Smooth, comfortable ride as one can expect.

cozzie55

I have considered run flats vs standard tyres but decided to stick with the run flats. I've driven other E90s with standard tyres and haven't noticed any difference.
either way i'd need to get my size sorted before i get to pick run flats or standards.

Ferris

cozzie55 wrote: »

How did you work out the percentages?
On oponeo i can't see options for m sport E90's which have are bigger than the standard E90.

I used the calculator -
http://www.oponeo.ie/tyre-guide/tyre-size-calculator