Panta Rhei said:
Then fitting 235/35 on offset 35 front will rub :thumbsdown: :thumbsdown:
Keeping in mind we are talking about michelin pss (which bascially have rectangular tyre edge).
225/35 on 8,5 are stretched too much I guess. BMW have beed doing 255 on 8,5).
This guy:
https://z4-forum.com/forum/viewtopic.php?f=49&t=86990&p=1285956&hilit=235%2F35#p1285956
Yeah they will be fine. Mine are 34 ET and 37 ET. I have 235/35/19 on the front and 265/30/19 on the rear and have had no rubbing what so ever, I'm also lowered on eibachs.
I am so confused.
It’s not that confusing, it’s just that there are a few variables at play.
Simply put, there isn’t a huge amount of room in the front arches and the design of the arch liners mean that anything beyond a moderate increase in width will generally cause some degree of catching on the liner, usually just behind where the headlight, wing and bumper come together, on the outside edge.
If you use the standard 18 inch wheel and offsets as your baseline (so, 8J and ET47) and assume a 225 section width tyre, anything that causes the wheel to stick out 15mm and above, risks causing rubbing. If your car isn’t lowered beyond M-Sport level, you may get away with more than 15mm, but if you are on Eibachs (for instance, as I am) you will (in my experience) be lucky to avoid rubbing with +15mm. On my slightly tired 70K original dampers, 13mm wider 18's caused some light catching. Changing to new shockers stopped it.
You can use https://www.willtheyfit.com/ to mess around with wheel width, diameter and offset, and it will tell you amongst other things, how far out your new set up will cause the wheels to extend beyond your current set up.
Variables are many, but perhaps explain why some people get rubbing and others don’t even on apparently similar setups. Typical critical variables include the condition of your springs and shocks - if they are worn, your car may be riding a little lower, or the shocks may not stop the suspension compression soon enough to avoid rubbing. Suspension alignment, for example how much camber you are running, will have an impact - more camber will tuck the wheels in at the top, which may help to avoid rubbing. It may also depend on the roads you typically drive on - straight, smooth roads may not induce the sort of movement in your suspension that results in rubbing - typically it happens on full compression or tight bends taken at speed. It may even just come down to the manufacturing tolerances of individual cars.
If you suffer from catching on the liner, there are a few things you can try; raise the height of the car (different springs, coil overs, thicker spring pads etc) or change the tyres - running a narrower section will change the cross sectional profile of the wheel and give you a few extra millimetres of clearance - hence the references to changing from 235 to 225 or even 215 section tyres. You can sometimes get the same effect from changing tyre brand (some have squarer shoulders than others) or use part-worn tyres, which will have lost a few mm.
If you do get tyre rubbing, as long as you haven’t pushed things to the extreme, you should be able to adjust things to relieve it - it just may take a bit of trial and error.
