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[NFiftyWon]

So I'm sure this has been discussed ad-nauseum, but the related threads unfortunately don't quite match my setup, so bombs away.


courtesy of holes (the pot variety??) I have 2 bent wheels and 2 cracked wheels. Tax money towards new wheels, yay. Let's make sure i don't have to do that again next spring. I need more Profile boys. I took a gander at the handy "XI Staggered Tire Calculation Tables". https://www.e90post.com/forums/showthread.php?t=1050762

I ordered the same wheel setup as before. staggered 18x8.5 ET35 F 18x9.5 ET35 R, 7mm spacers front, 15mm spacers rear. on ST-X coilovers bottomed out front and rear. I rub in the rear on dips. I think i can get away with the 45 profile in the front but the 35 in the rear is no bueno. so the current 225/45/18F ; 255/35/18R setup will need to be amended to accommodate the increase in rear profile. The chart doesn't really offer any solutions that i can come up with.. is is possible to run 245/40 on the front AND rear? Hmmmm

[E93Dude]

I don't have an answer for your specific question, but a bit of advice.

I had a very similar problem in 2016. Ran over large pothole which destroyed two front tires and bent same rims. I was running with run flats, which allowed me to limp to a Mr. Tire a few miles away, where they did a fair job of bending me over and raping my wallet. Joking aside, the rims were ordered from dealership and were "at cost". I was nearing needing four new tires anyway, so all in it was about $2,200.

Since that time I have avoided run flats. Regular tires are going to run a little softer, and should I hit a pothole again, I don't really care that run flats will take me to the nearest repair place. I am happy calling insurance and having it towed. Run flats are a great idea, but they are expensive and not always the best choice for every use case scenario.

245/40/18 works great on OEM sport springs and Bilsteins...I have no idea if that would be a good idea on something that is slammed though.

[nsjames]

Originally Posted by FCobra94

245/40/18 works great on OEM sport springs and Bilsteins...I have no idea if that would be a good idea on something that is slammed though.

my 245/40 winters rub in the front with 35ish offset 18x8 wheels.
on STX coils at a little lower than TUV approved. No where near the bottom.

245/40 on some enkei 18x8s with a slightly higher offset (37?) did not rub, but that was stock height.
So somewhere between stock xi and where i'm at you could run them.

[nsjames]

winter 245/40 is gold.
style 71s are 225/40 255/35
It rubbed just on the bumper where it meets the fender on bumps if the suspnsion was already compressed. Like a bump in the middle of the bottom of a dip.
not a ton, but enough to pop the corner on the passenger side on a real big one that got into the bumpstop all the way.

It may be worth considering raising the ride height a touch to accomodate them, since they're tall they don't have a huge gap.

[nsjames]

245/40 at stock xi height.

[NFiftyWon]

Originally Posted by nsjames

winter 245/40 is gold.
style 71s are 225/40 255/35
It rubbed just on the bumper where it meets the fender on bumps if the suspnsion was already compressed. Like a bump in the middle of the bottom of a dip.
not a ton, but enough to pop the corner on the passenger side on a real big one that got into the bumpstop all the way.

It may be worth considering raising the ride height a touch to accomodate them, since they're tall they don't have a huge gap.

my concern with running 245/40 on 9.5" width is that stretching would reduce the profile to about 35 anyways. is that a thing?

[nsjames]

I've never ran a tire not on a recommended wheel width, so can't say.