Cadillac XLR Forum Discussion, New wheels and tires installed in Past Cadillac Vehicle Discussion; After two long months, I finally have my new tires and wheels mounted on my 06 XLR-V.
Forgeline SP3S 20" ...
I was initially concerned that the ride would be harsher moving from the 19" to the 20" tires, but moving from run-flats to non-run-flats took care of that... in fact, I think that these new tires ride better and quieter than those Pirelli's that come OE (and the wet traction was terrible as well).
I guess the only downside is that I now have to carry a plug-kit and air-pump incase I get a flat.
I forgot to mention... when bolting on aftermarket wheels, you must remove the retaining clips that hold the brake rotors in place. They are placed on there during the build process at the plant to keep the rotors from falling off during assembly. There should be two per rotor at all four corners - they may not be there if your car has been serviced and they had to remove the clips to fix a problem.
What the clips look like (I shot it after half removing it so its easier to see):
The stock wheels have a little cutout for them, but aftermarket wheels don't and will cause your new tires and wheels will not seat correctly and they'll probably behave like they're out of balance.
What the back of stock wheels look like to accomomdate the clips:
Additionally, the TPM sensors for 05+ XLR's must use an RF tool to trigger them for the car to learn its position. If you want to buy one, the least expensive one I found that will work is the ATEQ VT10 for about $100. I ended up finding a local shop that had one and they took care of it for me. The process looks like this:
I got paranoid that I might get my new wheels/tires stolen - in fact, I had a nightmare that my V was on blocks after a day of shopping...
I did some research and ended buying some Gorilla Guard locking lug nuts... they have a spinning sleeve to stop thieves from using those lug nut removal tools (I've learned that such thefts are common and the regular locking lug nuts don't stand a chance against those tools.)