[Lazynok]

Just curious if the over all diameter of the tires is bigger fit the f34. My stock 18s come with I believe a 50 series tire... Which is one huge side wall. I haven't seen any f30 with this big of a wheel.

So my main question... Say I was going to get the 20" 361 rim... Which comes with a 30 series in the rear. Woul it look too small? Should it have a 35 for f34? Or in your case of aftermarket rims, should I go a tad higher profile?

Maybe this is why there are no rims on shopbmwparts for the f34... Cause if the over all diameter?

[lmcq784]

Yes, the F34 is equipped with a larger overall wheel diameter than the F30/F32.

If you're getting 20" wheels, a 30-series tire sounds too small - check the overall diameter yourself (as I don't know how wide the tire is).

Usually, they say to keep front & back wheel diameters within 1% of each other, and try to keep the wheels within 3% of factory specs.

[Lazynok]

OK thank you. Now I just need to figure out the size for 20x8.5 and 20x10...

[Richbot]

Look at overall diameter in the tire specs. You want circa 27"

[Lazynok]

Originally Posted by Richbot

Look at overall diameter in the tire specs. You want circa 27"

So far here are my options. They are 20x8.5 and 20x10


Which should I choose for the front? One is either a bit bigger than 27 and one isa bit smaller. And I think the 215 might stretch slightly cause is 8.46in wide and maybe become 26.9in? Closer... Which to choose?
215 40 20 8.46in 26.8in
225 40 20 8.8in 27.1in


Rear is spot on
255 35 20 10in 27in


Thanks

[pokerface]

the diameter of the F34 tires is the same as the F10 5 series, is it not?

[lmcq784]

Originally Posted by pokerface

the diameter of the F34 tires is the same as the F10 5 series, is it not?

I believe so.

[lmcq784]

FYI, my OEM (18" 400m staggered) sizes:

Front: 225/50R18 = 26.858"
Rear: 255/45R18 = 27.035"

My summer setup with Pilot Super Sports (19"x8.5" front, 19"x9.5" rear):
Front: 235/40R19 = 26.402" (1.700% smaller than OEM front)
Rear: 275/35R19 = 26.579" (1.689% smaller than OME rear)

No issues that I know of yet! Running great!
Originally, I was recommended 235/45R19 and 265/40R19, which would have been perfect, but PSS's didn't come in those sizes.