Hi, I need to pick up some winter tires for my car. According to my door my tire size is 245/40R19, which are apparently hard to come by and expensive. Now I don't fully know how to read tire sizes, but I know the stock size for a 2009 jag xf is 245/45R18. I have a set of steel rims that are 17", so by that logic, if I bought tires that are 245/50R17, would that fit on the car? I really don't care if I have big nice looking rims in the winter, I just want to make sure it's the right size or that it won't harm my car in some way.

 

This calculator will tell you how the new tires compare to the factory. Only issue could be if the wheel clears the caliper.


Tire Size Calculator - Tire & Wheel Plus Sizing


This one works as well. It will also tell you how the new wheel will fit on the vehicle with the given specs.


Online Wheel and Tyre Fitment Calculator. Offset, Tyre Stretch and Speedo Error | Will They Fit

 

What version of the XF do you have? If you have the Supercharged XF you won't be able to fit smaller rims over the brakes. You'll have to stick with 19's or larger.