[Smee]

need help please. I'm looking at wheels that are 9inch front 10.5 inch rear 20s.

the problem is I have xdrive

bmw say 225/35/20 fronts and 255/30/20 rears. these i think will be to much stretch.

what are my options on 9f/10.5r?

[alohasurftoad]

Originally Posted by Smee

need help please. I'm looking at wheels that are 9inch front 10.5 inch rear 20s.

the problem is I have xdrive

bmw say 225/35/20 fronts and 255/30/20 rears. these i think will be to much stretch.

what are my options on 9f/10.5r?

it will be stretched, not a fan

on x-drives, the difference between the front and rear diameter needs to be less than 1% (closer to zero = better)

245/35/20F(26.80), 285/30/20R(27.00), 0.75% diameter difference
245/30/20F(25.79), 285/25/20R(25.61), 0.15% difference

there may be other combinations

you choice of specific brand, tire, size become limited so you should consider this prior to purchasing your wheels.

[Smee]

Cheers

How does 235/35/20 and 275/30/20 measure on the scale?

[alohasurftoad]

Originally Posted by Smee

Cheers

How does 235/35/20 and 275/30/20 measure on the scale?

same diameter, which is great. tires will be stretching 1" on the front and 1/2" on the rear wheels. watch out for curbs.

[Smee]

Oh really I don't want stretch at all.

[alohasurftoad]

Originally Posted by Smee

Oh really I don't want stretch at all.

fwiw a 1/2" stretch is not much, it's stretching only 1/4" at each bead and angling the sidewall just slightly

245 is 1/2" stretch on 9", 255 is no stretch on 9", 265 slight bulge.

275 is 1/2" stretch on 10.5", 285 no stretch, 295 slight bulge.

the problem is finding aspect ratio/tire width combinations that is close to the OEM diameter of 26", difference in F and R diameters less than 1% and finally tire brand, model, size that exist for your chosen combination.

tbh i suggest you change the size of wheels, i.e. different width/offset, or look for different wheels that have width/offset more suitable to your needs.

[goj]

255s will not fit 10.5

[Smee]

Cheers so what size am I looking at for 225 front 255 rear?

cheers

[alohasurftoad]

Originally Posted by Smee

Cheers so what size am I looking at for 225 front 255 rear?

cheers

for the F3x series, OEM 20's are 20x8F, 20x8.5R with 225/255 respectively. start off with this in mind.

i suggest 20x8F, 20x8.5R or 20x9R with 225/255 OR 20x8F or 20x8.5F, 20x9.5R with a 235/265 combo if you want the staggered look.

since you are x-drive you may also consider going square. the car will handle better by reducing understeer, there will be no transfer case issues since all four tires are the same and you will be able to rotate however you desire.

20x8.5 with 245 or 255 or 20x9 with 255 all four wheels.

225 best fit on 7.5" wide
235 best fit on 8"
245 best fit on 8.5"
255 best fit on 9"
265 best fit on 9.5"
275 best fit on 10"

please use these or other similar sites and mess around on them. it's better that you do this and learn a bit than rely totally on forum responses.

https://tiresize.com/calculator/
http://www.discounttiredirect.com/di...170305201407:s

[Smee]

sorry one more 255/30/20 and 275/30/20

[.BMW.]

Originally Posted by Smee

255/30/20 and 275/30/20

The rear tire size is 2% taller than the front.

Not acceptable with xDrive.

[.BMW.]

These wheel widths, 9" front and 10.5" rear, in combination with xDrive and without stretching the tires is almost impossible.

The only tire spec that fulfills those requirements would be 245/30-20 front and 285/25-20 rear. But you need to chose offsets very carefully, or else those tires will rub (at least the rear)!

[Smee]

sorry been away and just got back so hadn't had a chance to reply.

so I am looking at velgen vmb6 in gun metal. f9 r10.5

I know the ET is 35f 45r on these wheels but I think if I get them I'm going great to go 235/35/20 and 275/30/20 as this seems the closest match.

would you agree ? and shouldn't get the rub on rear?