[floydarogers]

Originally Posted by jskin1510

Forgive me if this is a poor question but after reading this I wanted to clarify... Does only the tire size matter ? and not the rim size (width) as long as the tires are the correct sizes?

For example let's say 18x8 front and 18x9 with 235/40/18's all around... The width doesn't matter since the tires are all the same... is that correct?

Correct. The section width - 235 - is the width at the widest part of the tires (the bulge of the sidewall) , not the width of the tire bead or the tread. Unless the tire is quite "stretched" (mounted on a wheel so wide that the wheel is wider than the sidewall), the section width is the same on all wheels.

[gqbriel]

Hi guys,

I am also having a staggered setup 8J on 8.5J 17" M sport package on the xi.
I was wondering will :

225/45/17 and 245/40/17 will damage the X ,yes i saw the calculations and the difference is 1.02% - has anyone runned this kind of setup or if anyone is aware if it can cause issues with the car.
Unfortunately the 255/40/17 is a rare size and there is almost no option to choose from.
This tyre issue is the only bad side of the X so far and I am really not happy with that,i guess the only option if 245 cant do the job is 4x225's.

Thanks

[IAMPRATTE]

Hi guys. I am completely lost with staggered calculations. I am looking at a set of wheels size:
18x8.5 et35 front
18x9.5 et40 rear

Will this work on a 2008 328xi?

Thanks in advance.

[MeeChin]

Just bumping this back up to the top since has some great info

[zipstic]

Originally Posted by MARKET AL

Hi guys. I am completely lost with staggered calculations. I am looking at a set of wheels size:
18x8.5 et35 front
18x9.5 et40 rear

Will this work on a 2008 328xi?

Thanks in advance.

Yes, those wheel sizes will work. This thread is primarily focused on tire sizes however.

[rosica]

Glad a lot of people like my thread,

Some comments
- 245 and 255 have been done on the front so I included them, exact figment is required.
- Offset doesn't matter, width makes a marginal difference, I wouldn't worry about it.
- From my experience I recommend the stock stagger (in blue on table).

[E90joee]

Does anyone have pictures of the 18 staggered setup with 225/40 F and 255/40 R?

[SLOWER]

I want to do a square setup. 19x8.5 wheels with 235/35-19 tires. This is acceptable for xdrive, correct?

[Rahim e92]

Originally Posted by SLOWER

I want to do a square setup. 19x8.5 wheels with 235/35-19 tires. This is acceptable for xdrive, correct?

Yes.

[jimmydblock]

I'm ecstatic this thread is alive and exist thank you!

im looking to buy rims for 2007 328xi sedan:

18x8.5
18x9.5
both et 35 offset

now i know u said offset doesn't matter and width either but i dont want a huge bubble sidewall for a tire size, nor potholes bending my rims on the first bump in the road is my biggest fear.

im new to this wheel purchasing and i know the xi awd comes into play when the tires arent all the same so basically.

im assuming if i buy a setup of 225/40 or 235/40 ALL around it wont stretch the tire in the back? will the circumference be the same?

please recommend a tire size idk what to look for.

square setup beneficial for cornering, and great traction?

[jimmydblock]

Originally Posted by SLOWER

I want to do a square setup. 19x8.5 wheels with 235/35-19 tires. This is acceptable for xdrive, correct?

your daily drive isnt that rough id imagine, 19" geesh, can u post a pic of your tires once they're on please?

[SLOWER]

Originally Posted by jimmydblock

your daily drive isnt that rough id imagine, 19" geesh, can u post a pic of your tires once they're on please?

My daily drive is terrifying which is why I haven't gone 19 yet.

[jacklan]

You Are Awesome!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[matthewjmoser]

I have a lci 328 xi. and i put 235/35/19 on a 19x8.5 and a 19x9 . The tire brands are differen't front and back but the tread depth is the same. No lights or codes have been triggered. Say that this would pretty okay to just leave as is for now?

[mashimarho]

Bump.
Can we figure out 20's?
Something like 235/xx and 265/xx
or 245/xx to 275/xx

[twastheglow]

Sorry to bump an "older" thread, but what is the max variance that is allowed for revs per mile front to rear? I feel as previously stated, that comparing actual manufacturers specs is the best way to determine the front to rear variance on a staggered set up. For example, the 2 sets of tires in 2 different sizes I'm looking at have a small variance in revs per mile (set 1-FR 813, RR-818, and set 2-FR 800, RR 805). In this case there is a 5 rev per mile difference from front to rear. What is the maximum allowance to SAFELY run on our Xdrive?

[rosica]

Originally Posted by Aashenfox

After doing some chacking with the tire calculator posted at the top of this forum, and checking with a 3rd party (1010 tires calculator). I can only conclude that these tables are wrong. I checked 3 sizes in 19" and found all to be wrong. I didn't check any others after that.

235/35/19 and 275/30/19 are stated as having a 0.4% variance, for example. Its actually a lot less of a difference (5 TIMES less). More like 0.087%. This would make this the combo of choice for 19" wheels.

I strongly recommend people check for themselves using 1010 tires calculator before buying tires based on info in this thread.

BMW does not state any actual limits, forum consensus is 1% of diameter.

If you look the factory 19" option has a 5 rev/mile difference, make your own decision.

[rosica]

Originally Posted by SLOWER

My daily drive is terrifying which is why I haven't gone 19 yet.

19's suck for DD, just not enough sidewall

[solufotebi]

so would it be cool to run 225/40 18 front and 265/35 18 rear?

[fredcase]

this should be a sticky

[IAMPRATTE]

Originally Posted by floydarogers

Correct. The section width - 235 - is the width at the widest part of the tires (the bulge of the sidewall) , not the width of the tire bead or the tread. Unless the tire is quite "stretched" (mounted on a wheel so wide that the wheel is wider than the sidewall), the section width is the same on all wheels.

Forgive me if this is a dumb question...
If only the tire size matters and not the wheel width, then why would someone want to put tires with different aspect ratios on the front and rear? Does this number have to change based on tire width?

[twastheglow]

Originally Posted by MARKET AL

Forgive me if this is a dumb question...
If only the tire size matters and not the wheel width, then why would someone want to put tires with different aspect ratios on the front and rear? Does this number have to change based on tire width?

Yes. The aspect ratio (sidewall height) is a percentage of the width of the tread. So a 225/50 means the sidewall is 112.5mm tall. A 225/40 means the sidewall is 90mm tall. That means the rolling circumference between the two tires are different. The object is to get the sidewall height to be as close to identical as possible. The wider the tire, the lower the aspect ratio (sidewall height) has to be. The closer the sidewall height front to rear, the closer the number of times the tire will makes a full revolution within 1 mile.