Hey everyone,

I have a 2014 Q60 Sport coupe.

I have a set of mounted snow tires that were used on a 2013 M37 Sport.
Wheels are 18 x 8 and I know they will fit/work properly on my coupe. My question is the tires... and I think I know the answer but I need opinions more knowledgable than mine.

The tires are Blizzaks, 235/55R-18. I mounted them on the coupe, and the larger diameter is obvious. They really fill the wheel wells, but there are no obstructions or rubbing.

Should I use these tires, or replace them with tires of the stock size 225/50R-18? My obvious concern is ABS and the other electronic features for stability.

Thanks!

 

Those are almost 5% larger in rolling diameter which really isn't recommended, 3% seems to be the acceptable range. One thing in your favor is you'd be running squared, the front to back variance is what really can create havoc w/ these systems. Some guys on the Z boards go to significantly smaller tires for tracking and doesn't seem to create problems other than the speedometer being way off. Since you have the tires on hand you could always run 'em close to home and see if any issues arise.

 

I got 235/50/18 Goodyear Ice Grip WRT and they are pretty decent for the price and they are within the 3% rolling diameter.

 

Thanks for the informative response.

I called my Infiniti service advisor this morning, who check with his head technician. Their response is the electronic systems won't be adversely affected (ABS, traction control, etc.), but the speedo will certainly be off and I should drive it for a bit and see how the braking is, as it might take longer to stop. If accelerated brake wear is going to be an issue, I'll consider replacing the tires.

 

For the amount of time you'll be running the winter set I doubt the brake wear would be anything significant, not really any worse than running a considerably heavier set of 20" rims for example.

 

As others have pointed out, speedo wil read slower than you're actually going. Aside from that, traction control and other system relies on differences in wheel speeds between the wheels. With a square setup, I don't see why there would be any issues. Granted narrower tires are preferred for winter use, if you already have 'em why not make use of it.

Today is a good day to experiment, we finally got some snow around here, ~2" worth give or take.

 

Thanks, Jsolo. Yep, an inch or two, anyway! (But I have a brand new, highly detailed, gleaming Q60s in my garage. Take it out in this weather?)