[jeegunkim]

So my new wheels FINALLY came in. I ordered a set of Michelin Pilot Sport A/S 3+ in 245/35 and 275/35. The vendor is now saying the rear tires are backordered even though I specifically called in to make sure they were in stock before ordering - so frustrating. The only thing I can piece together for rear tires now are either 265/35 or 285/35 on eBay. Do you guys think I can get away with the 285/35 without any rubbing issues? The rear wheel spec is 19x10.5 +35 and I am lowered on Dinan springs + bump stops with an xDrive platform.

Let me know your thoughts!

[larrylam646]

Originally Posted by jeegunkim

So my new wheels FINALLY came in. I ordered a set of Michelin Pilot Sport A/S 3+ in 245/35 and 275/35. The vendor is now saying the rear tires are backordered even though I specifically called in to make sure they were in stock before ordering - so frustrating. The only thing I can piece together for rear tires now are either 265/35 or 285/35 on eBay. Do you guys think I can get away with the 285/35 without any rubbing issues? The rear wheel spec is 19x10.5 +35 and I am lowered on Dinan springs + bump stops with an xDrive platform.

Let me know your thoughts!

Hi jeegunkim,

A few comments:

1) Since you own an xDrive, you really want to keep the difference in circumference between the front and rear tires to less than 1%... the closer to 0% difference the better. So your front tires with a rear 275/35 should be 245/40.

2) The rear wheel spec (10.5 x 10.5 ET35) is aggressive for the G20. Compared to the OEM rear staggered wheel (19x8.5 ET40), your new rear wheels will stick-out 30mm and be 20mm closer to the suspension. I think you will have sufficient clearance to the suspension but you may rub (with a 275) on the fender liner, especially since you are lowered. You may want to consider a 30 profile tire for the rear (which means you should use a 35 profile tire in the front) but I cannot say a 30 profile tire in the rear will fit without some rubbing.

3) Have you used any of the online tire/wheel calculators to assess fit?

https://www.wheel-size.com/calc/?whe...cl=30mm&sr=0mm

I would suggest you compare your current rear setup to your desired rear setup using the tool I referenced and then apply the calculated differences to your current setup to assess fitment of your desired setup.

Larry

[jeegunkim]

Originally Posted by larrylam646

Hi jeegunkim,

A few comments:

1) Since you own an xDrive, you really want to keep the difference in circumference between the front and rear tires to less than 1%... the closer to 0% difference the better. So your front tires with a rear 275/35 should be 245/40.

2) The rear wheel spec (10.5 x 10.5 ET35) is aggressive for the G20. Compared to the OEM rear staggered wheel (19x8.5 ET40), your new rear wheels will stick-out 30mm and be 20mm closer to the suspension. I think you will have sufficient clearance to the suspension but you may rub (with a 275) on the fender liner, especially since you are lowered. You may want to consider a 30 profile tire for the rear (which means you should use a 35 profile tire in the front) but I cannot say a 30 profile tire in the rear will fit without some rubbing.

3) Have you used any of the online tire/wheel calculators to assess fit?

https://www.wheel-size.com/calc/?whe...cl=30mm&sr=0mm

I would suggest you compare your current rear setup to your desired rear setup using the tool I referenced and then apply the calculated differences to your current setup to assess fitment of your desired setup.

Larry

Hey thanks for the feedback.

I actually was able to find a set of 275/35's for the rear. Luckily Summit had it in stock.

On xDrive, what is the worst case scenario with running this 245/35 + 275/35 setup?

In terms of the aggressive fitment, it's actually what I wanted and there is another user on here running the same exact setup with wheels/tires/suspension and he hasn't had any issues. What I am unsure is if he is RWD or xDrive.

[larrylam646]

Originally Posted by jeegunkim

On xDrive, what is the worst case scenario with running this 245/35 + 275/35 setup?

There will be a 3% difference in circumference with your tire selection.

When I ran the OEM F82 wheel/tire setup (255/35 F and 275/35 R - a 2.1% difference) on my previous 435iX, the front transfer box did not like it and the front-end experienced clunking. My guess is the xDrive system was trying to compensate for the difference in rotating speed between the front and rear axles. What I have read on this forum is the transfer box may experience premature wear if the difference is >1%. I try to keep the difference as low as possible, typically <0.5%

Originally Posted by jeegunkim

In terms of the aggressive fitment, it's actually what I wanted and there is another user on here running the same exact setup with wheels/tires/suspension and he hasn't had any issues. What I am unsure is if he is RWD or xDrive.

I believe the rear suspension components (except for the springs/dampers) are the same so it should not matter if RWD/xDrive.

[jeegunkim]

Originally Posted by larrylam646

There will be a 3% difference in circumference with your tire selection.

When I ran the OEM F82 wheel/tire setup (255/35 F and 275/35 R - a 2.1% difference) on my previous 435iX, the front transfer box did not like it and the front-end experienced clunking. My guess is the xDrive system was trying to compensate for the difference in rotating speed between the front and rear axles. What I have read on this forum is the transfer box may experience premature wear if the difference is >1%. I try to keep the difference as low as possible, typically <0.5%



I believe the rear suspension components (except for the springs/dampers) are the same so it should not matter if RWD/xDrive.

Gotcha, I wonder if I should go with a 275/30 for the rear for 245/40 in the front. I'd prefer to go with 245/40 in the front, you think there would be rubbing issues?

[jeegunkim]

Just ended up order a set of 275/30, guess I'll need to return the 275/35. ugh.

[larrylam646]

Originally Posted by jeegunkim

Gotcha, I wonder if I should go with a 275/30 for the rear for 245/40 in the front. I'd prefer to go with 245/40 in the front, you think there would be rubbing issues?

Assume the first 245/40 is a typo and should have been 245/35.

Re rubbing with 245/40 tires, if your current tires are factory i.e. 225/40, the 245/40 tire will be 8mm taller. If the 245/40 tire does rub, it will likely rub the liner in-front of the tire while turning the wheel lock-to-lock.

I would suggest you measure the min clearance of your current setup while turning the wheel lock-to-lock and attempt to take into account the difference in wheel specs (since the new wheels are wider and may be position differently in the wheel well depending on ET) and tire height/width.

Originally Posted by jeegunkim

Just ended up order a set of 275/30, guess I'll need to return the 275/35. ugh.

So you are going with 245/35 and 275/30?

[jeegunkim]

Originally Posted by larrylam646

So you are going with 245/35 and 275/30?

Yup, 245/35/19 for the front, 275/30/19 for the rear. Should be safe with no issues?

[larrylam646]

Originally Posted by jeegunkim

Yup, 245/35/19 for the front, 275/30/19 for the rear. Should be safe with no issues?

I agree... a safe choice.

[jeegunkim]

Originally Posted by larrylam646

I agree... a safe choice.

Thank you man, really appreciate your experience and guidance!