Hello,
So after I swapped out stock 20s" for GTR staggered 20s, i noticed a slight shake/vibration/shudder while slowly accelerating around the 20mph mark. I should mention i'm lowered on BC coils. I've had the car aligned at the dealer, and tires were also balanced before I put them on. Told the tech at the dealer, said everything is fine. I dont know what it is. If its the tires, the suspension itself or what. Its been driving me crazy. Let me know if anyone had this issue and how to resolve.

Ty

You have an X. Are you sure you did the math right to make sure the wheels aren't messing with any systems? This is why people with AWD typically go 'square' and match wheel sizes.

Otherwise, as a general comment, the previous owner of my M56x reported shuddering to the dealer and the dealer replaced the torque converter. Previous owner reported this during 15-20mph. Something perhaps to look into.

Good point. I used the same size tires all around to compensate, with the rears slightly stretched. The variance is less than 1% difference. If it was an AWD issue would any lights come on the dash? I don't have any lights. I'll look into the torque converter issue.

Thank you.

Also, another thing to check (assuming you did but you never know) is if you need hub rings, etc.

Hello,

I had a similar problem when I first purchased my 2013 M56xS.

I changed out all of my fluids and it smoothed my car right out. Have them double check the wheels and make sure they don't have a minor bend or wobble to them.

Sometimes the tires need to be rotated on the wheel itself to smooth things out. Don't forget that the tires could be defective as well.

Good luck
Let us know what you find out
Andy

I was going to do the GTR wheels on mine as well

I was going to run
F-245/40/20
R-275/35/20

You shouldn't do the same tires on a staggered set of wheels

Good luck
Andy

The issue is still there. No awd lights. no issues found by the dealer. tires are brand new falkens. had them re-balanced and mounted. no bends in rims. Please let me know why i shouldnt run the same size tires. If I didnt run the same size tires the back wheels would stick out more to the point of rubbing. What size tires should I run so that the back tires fit to the wider rims without rubbing? I might have run the same size wheels all around.