how wide can I go

[notallthere]

ok I have a 2001 325i sedan and was looking at getting a set of wheels I know a guy with a set of 18's with the 5x120 bolt pattern so they will bolt
the front are 18x8 with a 38 offset and 235/40/18's I'm not to worried about these the the rear has me worried
they are 18x9 with a 40 offset and running 265/35/18's and I think these are just too big but if they fit I would like to get them thanks for the help guys

[Rooz]

Originally Posted by Rooz

Had a little time on my hand today...
Let's figure out the diameter of the factory setup...

Considering that 1 inch = 25.4 mm

Front: 225/25.4 = 8.8.....
8.8.... * .45 (45% of width is tire profile) = 3.9....

3.9... * 2 (top + bottom) + 17 (wheel size) = 24.97...

So the factory front setup is 24.97 inches tall

I'll spare you the explanations for the rear..

Rear 245/40/17 = 24.71 inches tall

Now, again.. I don't know too, too much if I'm correct but my guess is I need to come as close to those numbers as possible, right?

SO..... from what I calculated here's the closest setup I could think of on an 18" wheel....

Front: 235/40/18 = 25.4 inches tall
Rear: 255/35/18 = 25.02 inches tall

BUT... A 225/40/18 = 25.08 inches tall...HOWEVER being that the wheel is 8.5" wide (inside proportions so I am ASSUMING outside proportion is probably close to 9")

9" = 228.6 mm Meaning a 225mm tire would be too narrow for this wheel? AM I correct? And IF the wheel's INNER width is 8.5" then the 235/40/18 would be the proper setup, but if 8.5" is the outside width then 8.5" = 215.9mm, then the 225/40/18 would be perfect?

I posted that a long time ago, hope it helps

[notallthere]

thanks for the info but when it come to the conversions I'm ok I'm just more worried about rubbing with the width of the rear wheel

[Rooz]

255's you'r safe

265's you may rub

[notallthere]

I wonder if anyone on here is running then I just could get these on the cheap but if I have to get tires it not such a deal