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[fulltilt444]

I have a 2009 E90 X-Drive sport, stock suspension. I picked up a pair of 18" OEM rims from a M5/M6 (so I'm told). They currently have 245/45r18 but they are way too big for the car (I knew this when I bought them). Should I go with 245/40 or 245/35?

I currently have 225/45r17s.

The 245/35 is -0.891% smaller
245/40 is 2.893% larger

I already put the new wheels on, as I cracked one of the 17s and don't have a spare, figured I could drive like this to the nearby tire place. Rims look great, tires look a bit ridiculous. They rub at about 1/4 turn for whoever is interested.

Also, any comments on WRG3's? I can get a good deal on them. My only concern is above-normal summer wear...

[MonacoBlueE90]

Those look like style 184 http://www.bmwstylewheels.com/bmw/184. Specs are either 18x8 et14 or et20. Correct size from those two would be 245/40/18, but you could also consider 235/40/18 or maybe even 225/40/18. Are planning to lower it sometime? I mean with lowering the 245 isn't going to fit.

[fulltilt444]

Originally Posted by MonacoBlueE90

Those look like style 184 http://www.bmwstylewheels.com/bmw/184. Specs are either 18x8 et14 or et20. Correct size from those two would be 245/40/18, but you could also consider 235/40/18 or maybe even 225/40/18. Are planning to lower it sometime? I mean with lowering the 245 isn't going to fit.

Thanks so much! I wish I knew what offset I had. If I take the rim off I assume I can check?

So if I go 235/40 it will stretch the sidewalls in slightly so that I have more room? Not going to lower it anytime soon.

[MonacoBlueE90]

Originally Posted by fulltilt444

Thanks so much! I wish I knew what offset I had. If I take the rim off I assume I can check?

So if I go 235/40 it will stretch the sidewalls in slightly so that I have more room? Not going to lower it anytime soon.

Yeah basically, but 235/40 at 8 wide isn't stretched. Using that size you most likely ge rid off the rubbing when turning. You most likely find the offset from the back side marked like ET, IS, or something like that. There should also be 18x8 marked.

[fulltilt444]

Originally Posted by MonacoBlueE90

Yeah basically, but 235/40 at 8 wide isn't stretched. Using that size you most likely ge rid off the rubbing when turning. You most likely find the offset from the back side marked like ET, IS, or something like that. There should also be 18x8 marked.

Ok thanks! With your advice I ended up ordering the 235/40r18 Continental DWS, good price at 150/per compared to the Nokians. I'll post results if there are any issues.