[EwenMac]

again thanks for any input.

im aware of staggered wheel sizes, and on my 2007 e92 i have Star spoke

type 189 wheels 8J front and 8.5J rear

the specs call for 225/40 tyres on the front and 225/35 rear

i have Bridgestone Potenza run flats at the moment which i hate

so the question is why the profile difference front to back with the same tread width (225)

if i replace the tyres with non run flat tyres should i still stay with the different profiles ( by profiles im referring to the 40 front and 35 rear)

thanks

[Sgop335]

It is likely 255 35 on the rear not 225

[EwenMac]

See attached spec sheet, I would have thought 255 as well

[lookalikehuuh]

I think that screenshot has a typo, it should have 255/35.

It is important to notice that a 225/40 front and 225/35 rear would mean the rear sidewalls would actually be thinner sidewalls by 11mm that is simply not accurate.

a 225/40 front and 255/35 rear means the sidewalls are within .75mm of each other, this is what you want.

Also take notice that all others that have matching front and rears always match the aspect ratio (2nd number) because your front and rears need to rotate fairly evenly to prevent traction control from kicking in.

long story short... That's a typo use 225/40 front and 255/35 rear for correct fitment.

[EwenMac]

Thanks, that makes sense, as it is the rear tyres do look smaller in diameter, I was going to swap back and front, until I realised they were staggered width, although 1/2 of an inch is very subtle, so when these run flats are worn out, I’ll make the change