I was wondering if I can run 18" aftermarket rims for UHP summer tires and go back to stock 17" rims fitted with snow tires in the winter? Will that in any way compromise the speedometer? my actual mileage will be off, I believe. any other consequences for doing this? can this be done? Oh, this is for a base 04 TL.

 

Assuming you are running the proper sized tires, there will be no issues at all. Your speedo will only be off if you are running incorrect/alternate tire sizes.

 

Keep 235/45-17 winters and run 235/40 or 245/40-18 summers and you;re good to go!!

 

my buddy is trying to sell me:
5-Zigen ZR+ bronze wheels (18" x 7.5")
5 x 114.3 bolt pattern
Nitto Neogen Z-rated 225/40/18
I would use the oem 235/45/17 for snow tires...those 2 different sizes shouldnt be a problem. I think the lower height of the tire and the 18" rim cancel each other out.

 

If you stay within a few percent on the diameters, you're good to go.

Use this calculator: http://www.1010tires.com/TireSizeCalculator.asp


Why you'd go to a narrower summer tire though, I don't know. Typically you want to go narrow in winter (less snow plow) and wider - all else equal - for performance and/or looks.

 

I've been doing this the last 4-5 years. I bought a set of rims for my previous car when i owned it and had snow tires on the stock rims. Then i traded that off for this one and kept the new rims which had the same bolt pattern as the TL, so i put snow tires on the TL's stock rims. The speedo is almost the same between the two, 1-2 mph difference at 80mph.

It's nice to swap the rims during the season change, kinda changes up the look of the car. Plus you are wearing down 2 set of wheels, so you shouldn't have to buy tires for a couple years.

The only problem is storing the rims in their off season, but i built a rack for that.