[tmanm3]

Originally Posted by alohasurftoad

should be fine even after lowering

How were you able to know that so quickly? Im struggling trying to figure this piece out. I ideally want 20in wheels but have no idea where to even start for a staggered set up.

[alohasurftoad]

Originally Posted by tmanm3

How were you able to know that so quickly? Im struggling trying to figure this piece out. I ideally want 20in wheels but have no idea where to even start for a staggered set up.

a typical 19" wheel staggered setup that works without issues is 19x8.5 +35 front, 19x9.5" +40 rear. the offsets in your setup is just slightly lower, so it'll be further out by just 3mm in the front and 5mm in the rear.

[tmanm3]

Originally Posted by alohasurftoad

a typical 19" wheel staggered setup that works without issues is 19x8.5 +35 front, 19x9.5" +40 rear. the offsets in your setup is just slightly lower, so it'll be further out by just 3mm in the front and 5mm in the rear.

Thats great help. Thank you so much.

[alohasurftoad]

Originally Posted by tmanm3

Thats great help. Thank you so much.

no problem. if you scroll down to post #637 jackAdams has the typical setup that i talk about.

http://f30.bimmerpost.com/forums/sho...741571&page=29

for x-drive with 20" staggered setup i recommend fronts-20x8.5 +35ish with 235/35/20 (26.5" dia.) and rears-20x10 +42ish 275/30/20 (26.5")

[1QuikWS6]

Originally Posted by silver28

Did you buy your car used? I didn't think the F30 came with 225/40-18, I thought they were all 225/45-18. It honestly sounds like the wrong size. The 40 profile was for the E90's.

225/40/19, 255/35/19 are the stock tire sizes at least for my f32.

Purchased car new - I mistyped, original tires were 225/45-18 Conti RFT

[1QuikWS6]

Originally Posted by silver28

Here are all the % using 225/45/18 as the base tire. I wouldn't go more than+/- 1%

SIZE------ Diameter-----%
235-35-19 25.476 -1.9%
245-45-17 25.681 -1.1%
245-40-18 25.717 -1.0%
245-35-19 25.752 -0.8%
225-50-17 25.858 -0.4%
225-45-18 25.972 0.0%
255-35-19 26.028 0.2%
255-40-18 26.031 0.2%
255-45-17 26.035 0.2%
225-40-19 26.087 0.4%
235-50-17 26.252 1.1%
265-35-19 26.303 1.3%
235-45-18 26.327 1.4%
265-40-18 26.346 1.4%
265-45-17 26.390 1.6%
235-40-19 26.402 1.7%

Appears you are using the 1% spec comparing new tire sizes to original?

If that is not the case then disregard rest of post

That's not what the spec is about.

Spec refers to difference between front & rear tires installed on car regardless of what was originally installed. % difference between front and rear tire sizes cannot exceed 1% - reason is >1% front & rear tires will be rotating at speeds with enough difference to mess with mech/elec of AWD components

New tire dia. compared to original tire installed dia. has nothing to do with AWD problems - at most, your speedo will be slightly off one way or the other - from factory the speedo doesn't read correctly anyway so depending on which way you go, you may correct factory speedo offset & actually be reading correct speed

[silver28]

^ I was just trying to ensure you bought the right tire size and yes, comparing to 225/45/18. I definitely understand all the xdrive issues, all good.

I always try to stay within 1% of stock tire size. Obviously for speed sensor issues (although everyone says it's all off), but I've always read that it affects ABS sensors. Who knows.

[spuntyb]

FWIW, I'm going to try the following on my 335 xdrive since I found a great deal on some staggered Forgestar F14s here on the forums:

F 18x8.5 245/40/ZR18
R 18x9.5 285/35/ZR18

OAD difference is roughly 0.8%

[alohasurftoad]

Originally Posted by spuntyb

FWIW, I'm going to try the following on my 335 xdrive since I found a great deal on some staggered Forgestar F14s here on the forums:

F 18x8.5 245/40/ZR18
R 18x9.5 285/35/ZR18

OAD difference is roughly 0.8%

285 is 20mm oversize (bulging) on 9.5"

235/45 (10mm stretch) on 8.5", 265/40 (perfect) fit on 9.5" is a more suitable combination. 26.3"/26.3" diameter difference = 0%.

[spuntyb]

Originally Posted by alohasurftoad

285 is 20mm oversize (bulging) on 9.5"

235/45 (10mm stretch) on 8.5", 265/40 (perfect) fit on 9.5" is a more suitable combination. 26.4"/26.3" diameter difference = 0.4%.

I wondered the same. 285 just seems overkill, but thought of giving it a shot since those are the tires the wheels came with. The car is currently on a square setup, which I like, but the deal for this staggered set was too good to pass up. I think you're right though, I'll probably go for 265 on the rears.

[Karson1]

Originally Posted by 1QuikWS6

Actually, I run Mich PS A/S 3+ 245/35-19 Fronts (25.8" dia) & 275/30-19 Rears (25.6" dia) on 19x8.5 ET35 front wheels & 19x9.5 ET35 Rears for my summer setup

Tires fit the rims well with no stretch, offset + tire width puts them flush to the fenders with no spacers

Here are some charts for ix fitment:

Excellent chart. Can you please provide one for 20"? Can xDrive even run 20"?

[Karson1]

The other thing i noticed about the 18" and 19" charts are that all the tire size selections are in the 25" tire diameter range (look at all the Height numbers (diameter)). For xDrive, I believe the OE overall diameter (OAD) should be ~26". Therefore, the tire selections should start with 26" tires. https://tiresize.com/chart/. Am I correct? Please help - I'm a noob at this.

[alohasurftoad]

Originally Posted by Karson1

The other thing i noticed about the 18" and 19" charts are that all the tire size selections are in the 25" tire diameter range (look at all the Height numbers (diameter)). For xDrive, I believe the OE overall diameter (OAD) should be ~26". Therefore, the tire selections should start with 26" tires. https://tiresize.com/chart/. Am I correct? Please help - I'm a noob at this.

yes F3_ are 26", just use this tire size comparator.

https://tiresize.com/comparison/

[pnice1p]

I really do wish people wouldn't continue the myth about BMW and the 1% difference on xdrive. BMW sells cars that start at 1.2% themselves without any warnings. The BMW m235 xdrive came with 225/40/18 front and 245/35/18 rear. That's 1.2% diameter difference from the factory. These cars are not the e46xi cars. Those cars had to be very restricted. They do not resemble the newer xdrive system. Newer cars compute for rolling diameter on take of.

[vgore]

Originally Posted by pnice1p

I really do wish people wouldn't continue the myth about BMW and the 1% difference on xdrive. BMW sells cars that start at 1.2% themselves without any warnings. The BMW m235 xdrive came with 225/40/18 front and 245/35/18 rear. That's 1.2% diameter difference from the factory. These cars are not the e46xi cars. Those cars had to be very restricted. They do not resemble the newer xdrive system. Newer cars compute for rolling diameter on take of.

Where do you get your facts from? 225/40/18 front and 245/35/18 rear that is a difference of 0.4% and not 1.2%

[three40_6ix]

Should be fine. I'm running the exact same setup on my F30 340i.

[Kennybar112]

My experience with staggered setup on x-drive cars is understeer.

[The Godfather]

So I placed my 99 Firebird new set of MRR wheels and Continental Extremes tires on the F30 M xdrive. All fit perfect after adding a 3mm spacer in the back to clear the M calipers. Drove it for a bit but something feels off. A bit of hesitation on accelerating at any speed.

Fronts 245/35/19. 8.5 wide
Rears 295/30/19. 9.5 wide

My question is, what is my percentage on the above set up? Do I just change the rears to a 275/30/19 and be ok or will I have others concerns to look out for?

I saw on another thread someone stating NOT to go with the 35 F / 30 R profile. Any reason for this?

Thanks
First post.

[mrwilton]

Originally Posted by vgore

Where do you get your facts from? 225/40/18 front and 245/35/18 rear that is a difference of 0.4% and not 1.2%

Isn't that combination a 1.2% difference in diameter? Per tiresize.com it is.
I just want to make completely sure, since I would like to go to a wider front (245/40/18) which would be a 1.2% difference to the rear (255/40/18), but everybody is saying it has to be less than 1%.

Thanks!

Regards,
Wilton

[wdeerfield]

so im in the market for 235/265 combo and tire rack is severely limited on tire choices. is it that many manufacturers do not make these sizes or is it just a bad time of year for summer tires in these sizes?