need help with wheel fitment

andrewafc · 06-06-2018, 04:05 PM

hi I'm after some help/advice and I'm sure this is the right place!

i own a 2006 e91 m sport. i purchased some var alloys with tyres fitted. front fit fine but the rear I'm having rubbing issues. the wheels are 18inch 9.5j e22.

the rear tyres are 255/40/18 and i know the are a size to big ideally. with the new wheels fitted and two people sitting in the boot the wheel are is basically sitting on the tyre wall. this cannot be right?

I've put my old alloys back on and the car still seems to be sitting low. does the ride height look stock? I'm thinking the rear shocks could be gone causing the car to sit bit lower as more weight are on the springs.

has anyone come across like and issue like this or had any experience running this wheel tyre combination.

thanks
Andrew

tcphoto · 06-06-2018, 04:10 PM

They are the wrong offset, I imagine ET30 or higher would be ideal. I'm guessing that you got a hell of a deal on them. An ET22 is an M car fitment.

andrewafc · 06-06-2018, 04:21 PM

Quote:

Originally Posted by tcphoto

They are the wrong offset, I imagine ET30 or higher would be ideal. I'm guessing that you got a hell of a deal on them. An ET22 is an M car fitment.

ahh shoot!! i did get a pretty good deal, thats why i didn't do too much research before hand. does the car seem like its sitting low in your opinion?

eljay · 06-07-2018, 07:50 AM

As mentioned above, you have wheels with a very aggressive offset for E90. Not only is it ET22, the wheel width is 9.5".
I suggest you check the offset calculator in Wheels and Tires section (do it using desktop version of the forum to see it).
Plug in your OEM wheels/tires and your new wheels and tires. You will see by how much your new setup extends out.

The reason the car looks lower with your new wheels/tires is an optical issue. Your car's suspension is at the same height as before. But the car's fender arch "looks lower" for 2 reasons:
1. Wheel/tire extends out, so it's more flush with the fender
2. The tire size is wrong for E90. You need 255/35R18. Basically, your sidewall is taller, so it fills up the wheel well/arch more and the outside tire edge is physically closer to the fender arch.
The sidewall number is a percentage of width. Since you have 40 instead of 35 profile, your tire sidewall is 5%*255mm = 12.75mm taller than it should be. So your whole rear of the car is 12.75mm higher off the ground and the gap between the tire edge and top of fender arch is 12.75mm smaller.

06-06-2018, 04:05 PM	#1
andrewafc New Member 0 Rep 7 Posts Drives: bmw e90 Join Date: Feb 2018 Location: england iTrader: (0)	need help with wheel fitment hi I'm after some help/advice and I'm sure this is the right place! i own a 2006 e91 m sport. i purchased some var alloys with tyres fitted. front fit fine but the rear I'm having rubbing issues. the wheels are 18inch 9.5j e22. the rear tyres are 255/40/18 and i know the are a size to big ideally. with the new wheels fitted and two people sitting in the boot the wheel are is basically sitting on the tyre wall. this cannot be right? I've put my old alloys back on and the car still seems to be sitting low. does the ride height look stock? I'm thinking the rear shocks could be gone causing the car to sit bit lower as more weight are on the springs. has anyone come across like and issue like this or had any experience running this wheel tyre combination. thanks Andrew Attached Images
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06-06-2018, 04:10 PM	#2
tcphoto Brigadier General 3537 Rep 3,049 Posts Drives: E92 335i 6MT Coupe Join Date: Dec 2009 Location: Nashville, TN iTrader: (1)	They are the wrong offset, I imagine ET30 or higher would be ideal. I'm guessing that you got a hell of a deal on them. An ET22 is an M car fitment. __________________
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06-07-2018, 07:50 AM	#4
eljay Colonel 1444 Rep 2,127 Posts Drives: ///M + E91 Join Date: Jun 2010 Location: NS iTrader: (1)	As mentioned above, you have wheels with a very aggressive offset for E90. Not only is it ET22, the wheel width is 9.5". I suggest you check the offset calculator in Wheels and Tires section (do it using desktop version of the forum to see it). Plug in your OEM wheels/tires and your new wheels and tires. You will see by how much your new setup extends out. The reason the car looks lower with your new wheels/tires is an optical issue. Your car's suspension is at the same height as before. But the car's fender arch "looks lower" for 2 reasons: 1. Wheel/tire extends out, so it's more flush with the fender 2. The tire size is wrong for E90. You need 255/35R18. Basically, your sidewall is taller, so it fills up the wheel well/arch more and the outside tire edge is physically closer to the fender arch. The sidewall number is a percentage of width. Since you have 40 instead of 35 profile, your tire sidewall is 5%*255mm = 12.75mm taller than it should be. So your whole rear of the car is 12.75mm higher off the ground and the gap between the tire edge and top of fender arch is 12.75mm smaller.
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