Largest 18" tyres that won't scrub

[Dfreeman]

I have an '06 Z4 Coupe with the 18" M alloys - 18x8 front and 18x8.5 rears. Can anyone tell me what sizes I can go up to without scrubbing the tyres? Research I hvae done so far seems to indicate that 235/35-18 front and 265/30-18 rears should be fine, but is there a slightly wider option on 18's that will fit ok?
Thanks

 

[mmm-five]

I've got 265/40r18s on my Z4MC and they've only rubbed once or twice on heavy compression (e.g. hard left-hand turns at high-ish speed, with bumps, on track), so it will depend on how you use the car.

You might be able get away with 285s on the rear and 245 on the front without rubbing, but only if you drive everywhere at 10mph, don't turn any corners, and don't have to negotiate any bumps.

It's also worth noting that some 265 profile tyres are wider/narrower than others and the only way to find the actual width out is to measure one (the manufacturer sites are a bit useless for this information).

You've also got the added complication of having the wrong offset wheels in the first place, so the tyre isn't central in the arch.

Is there any reason (other than cosmetic) that you want wider tyres, as the won't improve the handling if you have to go down to a 25 profile one to make it fit.

 

[Dfreeman]

Thanks for the info. Purely cosmetic at this stage. I don't plan on doing any track work for now, although I don't want to go too radical and make the handling suffer too much.

 

[sars]

If you want the wheels to "stick out further" then fit spacers, have a search but there are a few who have used 10mm or so without issue. Bing for one has

If you just want wider tyres you won't notice a great deal of difference in an extra 10mm i.e. 255 to 265