Question about tire fitment

[BreakMyWindow 1874]

I have 235/45/17 tyres all round on my e39 540.

I am wanting to fit 255 width tires on the back, but am not sure if they will fit. The rims are the same as the ones pictured 17"x8" size. Would I be able to fit 255 width tires on an 8" wide rim ?

[bravo 35]

Just OK, 255 are better on a 9" rim, and will look a little odd on a 8" but not so wide that they can't be fit.

You will want to go to a 40 aspect ratio though (ie 255/40/17)

Edit: also beware that you will have around 10mm less clearance inside and outside, so if your rims, etc only just clear the struts/bodywork now, you may be in for trouble.

Edited July 8, 2008 by bravo

[BreakMyWindow 1874]

Thanks! so in terms of looking odd.. the sidewalls of the 255's will not look perpindicular to the road when looking side on?

[bravo 35]

No, but they will tend to angle out a bit from the bead to the edge of the tyre. Talk to who you plan to fit them for you. If you go somewhere decent, they will know what they are talking about and can probably even show you an example.

[jochen 4]

I have 235/45/17 tyres all round on my e39 540.

I am wanting to fit 255 width tires on the back, but am not sure if they will fit. The rims are the same as the ones pictured 17"x8" size. Would I be able to fit 255 width tires on an 8" wide rim ?

The permitted tyre sizes are clearly described in the owners manual

Anything else and you will possibly run into clearance problems.

[BreakMyWindow 1874]

The permitted tyre sizes are clearly described in the owners manual

Anything else and you will possibly run into clearance problems.

Yep! have seen that 255's are permitted for the e39 540.

[jochen 4]

Yep! have seen that 255's are permitted for the e39 540.

If that's the case, they will fit and clearance will be fine.

[BreakMyWindow 1874]

If that's the case, they will fit and clearance will be fine.

clearance shouldnt be an issue, its if they will fit on an 8" wide rim that they may be a problem.. id suspect the wider 18" versions of my rim have a different offset to allow the wider tire to be fitted.

[kiwi535 538]

clearance shouldnt be an issue, its if they will fit on an 8" wide rim that they may be a problem.. id suspect the wider 18" versions of my rim have a different offset to allow the wider tire to be fitted.

8 inch aint very wide for an e39 look on http://www.realoem.com/bmw/,you can punch in your chassis number and see all the wheel sizes that were optional beleive me 8 inch isnt he widest.Its only when you into the 9.5 etc that the offset goes away from 20mm Edited July 10, 2008 by kiwi535