My 03 540 sport has the M parallel rims and the back rim is 9" wide. When I replace my tires I was thinking of going one size wider (so they will be a bit taller) front and back to help correct the speedo error. The fronts will fit just fine, I was just wondering if anyone else has put a 275 on a 9 inch rim? Tirerack says that it should work, but I would like to see if anyone else has tried it!

thanks
Matt

My 03 540 sport has the M parallel rims and the back rim is 9" wide. When I replace my tires I was thinking of going one size wider (so they will be a bit taller) front and back to help correct the speedo error. The fronts will fit just fine, I was just wondering if anyone else has put a 275 on a 9 inch rim? Tirerack says that it should work, but I would like to see if anyone else has tried it!

thanks
Matt
Ive got M-parallels too with a 9.5 rear wheel and Im only going with a 265/35/18. Your 275 will be wider on a smaller wheel. hmmm I dont know :dunno Post your results, If they fit I might go up a siz :stickoutt e

Tell me about your rims? how did you get a 9.5" rim, I thought they were all 9"
Maybe I can get 9.5" rims for the rear?

265s fit fine on a 8.5" wheel, I see no reason with another half inch that you couldn't run another 10mm. Something else to consider is that some tires run wider than others. I say go for it.

Tell me about your rims? how did you get a 9.5" rim, I thought they were all 9"
Maybe I can get 9.5" rims for the rear?
Thats how they came when I ordered them. I got the set off ebay. wheels and tires for about $1400 I think, Its been over a year. I just looked for the reciept and cant find it. 18x8 front, 18x9.5 rear. Cheack ebay they are there. And you prolly could fit 275 on there, I didnt wanna risk it and have to roll the fender.

My 03 540 sport has the M parallel rims and the back rim is 9" wide. When I replace my tires I was thinking of going one size wider (so they will be a bit taller) front and back to help correct the speedo error. The fronts will fit just fine, I was just wondering if anyone else has put a 275 on a 9 inch rim? Tirerack says that it should work, but I would like to see if anyone else has tried it!

thanks
Matt
"Should" is the key word here. Can they gaurantee it? What if you buy, they ship, and they dont fit......then what.
"Should" is not good enough. They "SHOULD" know for sure.

Thx.
The Tirerack website says that the 275/35/18's will mount on rims from 9" to 11". Some of the tires specs say that 9.5" is the minimum, so I wouldnt go with those. But most do say 9" is OK, I was just wondering if anyone had done it. :help

What size are your current tires? Going wider doesn't necessarily mean taller, so it woun't have any impact on speedo readings. I don't believe you even have a speedo error problem, or a very, very slight one. You would have to be really off in terms of your overall wheel/tire diameter compared to the OEM diameter. Sticking with the more "proper" recommended tire size for a given wheel width keeps you very close or the same overall tire diameter as OEM. In any case, I wouldn't put a 275 on a 9" wheel, although it may fit. If your lower the car, the 275's will cause rubbing with the rear fender unless you roll them.

Tell me about your rims? how did you get a 9.5" rim, I thought they were all 9"
Maybe I can get 9.5" rims for the rear?

There are two types of M-parallels produced by BMW:

E39 M-parallels with 74.1mm center bore: 8" front ET20, 9" rear ET22

E38 M-parallels with 72.56mm center bore: 8" front ET 13, 9.5" rear ET25

While someone with an E38 could use your rims, you couldn't use theirs since the center hub bore on an E38 rim is too small for your E39 hub flange.

Hope that helps.

Also, to answer your original question... a 275 is too wide for a 9" rim in my opinion.

A 275 tire has a section width of 275mm. Your 9" wheel is 228.6mm. While you might be able to get it to fit if the tire doesn't run wider than anticipated, it might look a little weird.

Ok, here is my reasoning on the tire size. The stock (non-sport) tires on the 5 series are 225/55/16, and they are 25.7" Diameter. The 235/40/18 and 265/35/18 on my Sport package car are about 25.4" - 25.3" in Diameter. This is enough difference to make the speedometer read faster than the car is traveling.
Now, the M5 sizes of 245/40/18 and 275/35/18 are approximately 25.7" -25.6" so this is almost exaclty the same rolling diameter as the stock, standard tires on all 5's.
This slight difference in rolling diameter will halp bring the speedometer error down some.
(of course all measurements are totally dependant on the brand of tire, not all 275/35's are exactly the same diameter)

According to realoem.com the E39 rears are 18 X 9 Et24, it is the M5 rims that are 18 x 9.5 Et22

The official word from tirerack is that the 275 will fit on the 9" rim... But the fenders may need to be rolled.

Oh I almost forgot, I dont plan on lowering the car, so that is not an issue for me.