[Avionax]

Hello, i have 18" bbs rc2 reps that came with the car when i bought it. The front wheels are 8.5j, and 10j rears. They are with 225/40/18 and 255/35/18 tires as is the standard xdrive size, but they cause jittering during acceleration and my mechanic was 100% sure that it was the transfer case going bad but since i put my winter square setup 8j 225/45/17 i haven't had these symptoms.
I was told that my rear tires were too stretched and that caused my problems, is it true?
If so what size tires will work best for those rims?
Thank you very much 😁

[Bimmer_Bro]

Originally Posted by Avionax

Hello, i have 18" bbs rc2 reps that came with the car when i bought it. The front wheels are 8.5j, and 10j rears. They are with 225/40/18 and 255/35/18 tires as is the standard xdrive size, but they cause jittering during acceleration and my mechanic was 100% sure that it was the transfer case going bad but since i put my winter square setup 8j 225/45/17 i haven't had these symptoms.
I was told that my rear tires were too stretched and that caused my problems, is it true?
If so what size tires will work best for those rims?
Thank you very much 😁

No stretched tires would not cause a jittering . 10 inch rim is the proper size for those so they really shouldn’t be stretched at all.
With staggered you want to keep the circumference within 1% of the front vs the rear to keep the xdrive happy. (You are .04%)

Could be the transfer case or something else out of balance.
Do they shake even when just cruising ?