I ended up buying 4 used 215/40/17s and 2 of them were focked up so i just put the two in front end kept the same 215/50/17 in the back.

i left the tire spot and like a minute later the ABS/SLIP AND VDC OFF came on and then i went back and got it checked and he gave me an excuse and he said it would be fine. i then drove home and then tried going back out but my brakes were acting funny and heard one of the sensors going off.

did anyone replace with a smaller size in diameter and get the same issue? or know if this should happen? the customer service for infiniti is closed on weekends so i couldn't ask them. thanks for the info guys!!!

 

I never had this particular issue, but if I remember correctly, because of the different diameters on the front vs. rear, the computer senses differing rotational speeds, and hence "thinks" there a traction problem. The computer will either cut power or apply the brakes to correct the problem it's sensing.

You've got to get one of the two sets changed.

 

This is very big difference in diameter-more than 2"!. I suggest you get all 4 the same size asap. Get rid of 215/40.

 

Do you have the AWD model? Regardless you can't change the diameter of the wheel by that much (greater than 9% in your case) without affecting the VDC..etc.

As suggested, lose the 215/40's, they are too small for a 17" rim.

 

thanks guys

 

If you keep your VDC off you will be ok. I have the same problem with my oem wheels I use from time to time. The overall diameter is off too far and the car thinks it's loosing traction.