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[kaigoss69]

Hey Guys,

just picked up these wheels used. The specs are as follows:

Fronts: 18x8.5 +38
Rears: 18x9.5 +35

I was thinking about going with Michelin PSS 245/40/18 and 275/35/18 on this stock set-up (not lowered). The other option would be 235/40/18 and 265/35/18.

I currently have a 15 mm spacer on the rears with the OEM style 162 wheels. So my other question is can I keep the spacers or would that push the tires out too much and cause rubbing? I am leaning towards taking them out.

I understand the PSS run a bit wider than most other tires, so I want to make sure I select the correct tire size.

Another HUGE factor for me is rim protection. The PSSs have a small lip on them that protects the rims somewhat from curb rash. I understand that this does not fully protect from curb rash, but it helps. So I was thinking to go with the 275/245 combo since this causes the sidewalls to push out a little more past the rims.

Any advice, especially from users who have run similar set-ups, is greatly appreciated!

[Rival]

235 & 265

do you plan to alter things.....roll fenders?? etc..??

[kaigoss69]

Originally Posted by Rival

235 & 265

do you plan to alter things.....roll fenders?? etc..??

No not wanting to alter anything unless absolutely necessary. Why the smaller tires?

[kaigoss69]

Bump, been doing a lot of reading but have not found anyone with a similar set up.

Another thing I would like to discuss is the fitment of 275 wide tires on 9.5 inch wheels. to me it sounds like this would be a near ideal fitment, if not a tad small based on the OEM fitment of 255 wide tires on 8.5 inch rims, which is what I have now on the rears. going from 8.5 inch rims to 9.5 inch rims represents an increase in width of roughly 25 mm. The increase from 255 to 275 is 20 mm. therefore, the 275 mm wide tire on a 9.5 inch wheel is still 5 mm less than the fitment of the 255 mm tire on the 8.5 inch wheel. Therefore I do not see the problem of going for 275 mm wide tires. In fact, a 285 mm wide tire should still fit fine because it is only 5 mm wider fitment then the OEM set up. Am I missing something?

[ApexWheels]

The ideal tire size would be 235/40/18 front, and 265/35/18 rear. You can certainly run a 245 front tire, but the overall rolling diameter becomes short with a 35 profile, and tall with a 40 profile. For this reason, we recommend a 235/40/18 with a 8.5" wheel. In the rear, the 265/35/18 will fit perfectly without any modifications. You can move up to 275/35/18's, but you may need to roll your rear fenders to prevent rubbing.

Do not base your selection off of the 8.5" wheel with 255's. A 255 tire is quite large for an 8.5" wheel, and not ideal. To have some decent sidewall support, you would want at least a 9" wheel for a 255 tire.

- Ryan

[kaigoss69]

Originally Posted by ApexRaceParts

The ideal tire size would be 235/40/18 front, and 265/35/18 rear. You can certainly run a 245 front tire, but the overall rolling diameter becomes short with a 35 profile, and tall with a 40 profile. For this reason, we recommend a 235/40/18 with a 8.5" wheel. In the rear, the 265/35/18 will fit perfectly without any modifications. You can move up to 275/35/18's, but you may need to roll your rear fenders to prevent rubbing.

Do not base your selection off of the 8.5" wheel with 255's. A 255 tire is quite large for an 8.5" wheel, and not ideal. To have some decent sidewall support, you would want at least a 9" wheel for a 255 tire.

- Ryan

Thanks Ryan, really appreciate your input. I want to go with 245 fronts to get extra rim protection, does that make sense? In that case which is the lesser of the 2 evils, having a larger or smaller diameter than stock?

[ApexWheels]

Originally Posted by kaigoss69

Thanks Ryan, really appreciate your input. I want to go with 245 fronts to get extra rim protection, does that make sense? In that case which is the lesser of the 2 evils, having a larger or smaller diameter than stock?

The 245/40/18 will have a difference of -1.634%, whereas the 245/35/18 will have a difference of 2.178%. It comes down to tire selection as well, as you may only find one size or the other in the compound that you are looking for.

- Ryan

[kaigoss69]

Originally Posted by ApexRaceParts

The 245/40/18 will have a difference of -1.634%, whereas the 245/35/18 will have a difference of 2.178%. It comes down to tire selection as well, as you may only find one size or the other in the compound that you are looking for.

- Ryan

So just to clarify, the only real "negative" here, with either choice, is speedometer error, correct?

[bmw325i]

I had the same size with 19" Hankook v12s 245/35 and 275/30 and et35 in the front . The rear was kind of close without anything done to the fenders. If you have closer to 1.7-2. degrees of camber you shouldnt have problems. I had -1.5 degreees in the rear.

[ApexWheels]

Originally Posted by kaigoss69

So just to clarify, the only real "negative" here, with either choice, is speedometer error, correct?

Not necessarily, that is just one aspect. Different size sidewalls will have a direct translation to how the car feels/handles. Furthermore, a taller sidewall will increase the risk of rubbing the fender liners depending on tire type, ride height and alignment settings. Most of the time an e9X 3 series can run either the 245/35/18 or 245/40/18 without rubbing issues up front.

- Ryan

[kaigoss69]

So I have decided to go with 245/35/18 fronts and 275/35/18 rears. Any objections? Here is the calculation & visualization compared to OEM.

[ZTUNER]

I run 275/35/18 rear and 245/35/18 front on 18 x 9 wheels with no issues.

[kaigoss69]

Originally Posted by ZTUNER

I run 275/35/18 rear and 245/35/18 front on 18 x 9 wheels with no issues.

What are your offsets?

[CoffeeBean]

Originally Posted by kaigoss69

Another thing I would like to discuss is the fitment of 275 wide tires on 9.5 inch wheels. to me it sounds like this would be a near ideal fitment

It is. That's what I'm running on 18x9.5 with +30 offset. I couldn't go any wider without rubbing. Your offset is +35 so it won't be as flush, but 5mm difference isn't much. I would assume you'd still have enough clearance on the inside, but I can check mine for you.






This is with it jacked up on the other side to show the clearance.

[EJ_3]

Enkei Konjin

18x8.5 et35 245/40 18
18x9.5 et35 285/35 18

[kaigoss69]

Thanks guys. Got everything installed. Turns out the 275/35/18 tire does not give much rim protection at all. Perhaps next time I'll go with 285/30/18 size.

Looks good, and tires ride awesome. Now of course it is screaming to get lowered! Am I correct in the assumption that if I do not get any rubbing now, I should not get any rubbing with a lowered suspension?

[CoffeeBean]

Not necessarily, but I know you won't with that offset. BTW I checked the inside clearance on mine and there's plenty of room.

Car looks great!

[classyfast]

Originally Posted by ApexRaceParts

The 245/40/18 will have a difference of -1.634%, whereas the 245/35/18 will have a difference of 2.178%. It comes down to tire selection as well, as you may only find one size or the other in the compound that you are looking for.

- Ryan

Sorry to jack but can I run a 245/40/18 snow tire on a staggered set of oem 193m wheels?

[HB E90]

Originally Posted by kaigoss69

Thanks guys. Got everything installed. Turns out the 275/35/18 tire does not give much rim protection at all. Perhaps next time I'll go with 285/30/18 size.

Looks good, and tires ride awesome. Now of course it is screaming to get lowered! Am I correct in the assumption that if I do not get any rubbing now, I should not get any rubbing with a lowered suspension?

Looks good. I like those wheels. Question would that work on a LCI model? Do you have 8mm+ clearance to the fender?

[Alex09_335]

Originally Posted by classyfast

Sorry to jack but can I run a 245/40/18 snow tire on a staggered set of oem 193m wheels?

If your talking about the rear you might be able to swing it. but the tire is 0.7" taller so 0.35" bigger radius. If you have X-drive might not be the best idea to have different sized tires on front/rear

Best bet for rears would be to drop to 245/35/18 or bump to 255/40/18

For my winters I have them set up on my stock BMW rims and they are 225/40/18 front and 255/35/18. They look great and work awesome in the snow, definitely a little harder to find the rear tires tho.

Check out Pirelli Sottozero 3 if your ditching the runflats or Sottozero 2 if you have runflats.

The Sottozero 3 preforms much better in snow I find so I bit the bullet this year and purchased the supersaver spare tire kit from the dealership for some added piece of mind on the road. (don't let a tire retailer tell you they don't exist because they do and find a better retailer that's willing to order them)

[classyfast]

Originally Posted by Alex09_335

If your talking about the rear you might be able to swing it. but the tire is 0.7" taller so 0.35" bigger radius. If you have X-drive might not be the best idea to have different sized tires on front/rear

Best bet for rears would be to drop to 245/35/18 or bump to 255/40/18

For my winters I have them set up on my stock BMW rims and they are 225/40/18 front and 255/35/18. They look great and work awesome in the snow, definitely a little harder to find the rear tires tho.

Check out Pirelli Sottozero 3 if your ditching the runflats or Sottozero 2 if you have runflats.

The Sottozero 3 preforms much better in snow I find so I bit the bullet this year and purchased the supersaver spare tire kit from the dealership for some added piece of mind on the road. (don't let a tire retailer tell you they don't exist because they do and find a better retailer that's willing to order them)

awesome, thanks for the suggestion !

[Sebis]

Originally Posted by kaigoss69

Thanks guys. Got everything installed. Turns out the 275/35/18 tire does not give much rim protection at all. Perhaps next time I'll go with 285/30/18 size.

Looks good, and tires ride awesome. Now of course it is screaming to get lowered! Am I correct in the assumption that if I do not get any rubbing now, I should not get any rubbing with a lowered suspension?

Looking great, how do you like the wheels? Any rubbing? What kind of tires did you get?