Hello all. 2015 XF. Found a great deal on new Michelin Pilot tires size 245/45R19. Wondering if the increase in aspect ratio from 40 to 45 would be problematic. Help a guy out! Thanks.

 

It will make your speed/mileage inaccurate.

 

thanks. Wondering if the tires will scrape in the wheel wells?

 

IDK

 

https://tiresize.com/tyre-size-calculator/

 

2015 XF - I'm going to take a wild guess as say thats the previous gen x250 XF, in which case - wrong forum.

I can more or less confirm that 245 45 R19 will rub - specifically, against the fender liner. I tried 255 45 R19 (front) and 285 40 R19 (rear). While the rears were okay, the fronts were rubbing on full lock. You shouldn't be concerned about the speedometer reading, thats negligible. If you are absolutely adamant on getting the tires, then I would take a heat gun and deform the fender liners (inwards). This won't hurt your car, the fender liners are made up of soft plastic and even if you were to leave them, the rubbing is minimal, you'll just hear a mild squeak (rubber against plastic) on full lock.

 

In the past when upsizing wheels or tires, I have experimented first. Go to one of those bargain "used tire" places on the poor side of town and for $40-$50 have them mount a used tire in the overall dimensions you want to try. Then take it home, mount it on one corner of the car, drive it very slowly out into the street and then make tight turns each way going up and down the incline into your driveway, rolling the test wheel onto the curb so that you get near full compression at full lock. If it doesn't touch anywhere, go carefully for a short, slow drive to a local empty parking lot with speed humps and do a little more testing with the radio off and the windows down. Repeat for each corner. If you don't hear any rubbing, then go ahead and place the order for four brand new wheels or tires. Your speedo may be off but if you can do math in your head.... Old cars with cable driven speedo's could be corrected but I'm not sure about the XF. I'm running a taller tire, to improve the ride quality, but not that size, I'm on 18's. Ironic how when I was younger, sports cars were made too soft and I had to modify suspension and upsize wheels for SCCA and now that I'm old, luxury sedans all come race-prepared right out of the factory and I have to modify suspension and downsize wheels to get even a halfway decent ride.