I have a 2005 G35 Couple with 225/45/18 on the frton and 245/45/18 on the rear. Would it look bad or cause any sort of problem if I put 255/40/18 on the rear? I know the tire would be 0.6" shorter, 0.3" wider and I would get a 2.5% speedometer error. But I was wondering if anyone had used this size before and could comment on the looks. Thanks.

 

My snows are 245/40/18's all around. Car looks fine and no issues with the VDC. Car is a bit lower and the lower gearing actually makes the car feel a bit quicker off the line.

 

i was thinking about getting 225/40/18 for the front tand 245/40/18 in the rear, would this be ok or would it cause a speedo error?

 

There is about an inch difference between the stock OEM 245/45 and the 245/40.
Your speedo would show around 2mph faster than your actually going.
Example...60mph on speedo....
57.8 actual speed.

 

There's no problem running 245/45X18 in the front but I'd stay with the
45 series out back since you're probably using OEM wheels....no reason to
change.
Gary