[pattie]

im confused also, i have mv3 rims with 255/35/18 rears and 225/40/18 front but cant understand why the fronts are 40 and the rear 35, and need to know what are the largest set of rims and tyre combo i can have on my pre face lift e91 330d m sport can have

[HighlandPete]

Originally Posted by pattie

im confused also, i have mv3 rims with 255/35/18 rears and 225/40/18 front but cant understand why the fronts are 40 and the rear 35, and need to know what are the largest set of rims and tyre combo i can have on my pre face lift e91 330d m sport can have

The 35, 40, 45, figure is an aspect ratio. So to keep the side wall height, (wheel diameter) the same, as you go for a wider tyre, you must change (downsize)the aspect ratio to keep the wheel the same diameter. If you don't and keep the aspect ratio the same, as you widen the tyre section, the wheel would become bigger.

The different sizes therefore keep the RC (rolling circumference) near identical on front and rear wheels.

HighlandPete

[rich1068]

I've ordered the Continentals at £840 including fitting. I can claim the VAT back too so not too bad. Just waiting on a delivery estimate.