i want to put 20" rims on my cadillac xlr. the wheels are staggered. they are 20x8.5 in the front and 20x10 in the rear. both have a +35 offset. im putting 245/35/20 tires in front and 275/30/20 tires in the rear. can these fit cleanly?? with no rubbing and ould it clear the calipers?? thank you!!!

NicklZ:

Here is some info that may or may not be useful:

1. I run 20 x 8.5 rims with 255/35 tires on all four wheels that have about a 35-40 offset with no problem on any wheel. Therefore, from experience, you should not have a wheel well rubbing problem on the fronts. I cannot comment on the rear wheel clearance, with the 10 inch wide rims.

2. The correct offset, wheel width, or diameter do not necessarily guarantee brake caliper clearance. You got to go to the wheel manufacturer for that information because the spoke design geometry comes into the picture. You sure don't want to end up having to use spacers.

3. The combination you are stating will give you a total diameter in front of 26.75 inches and 26.50 inches in the rear. These are close enough so that the car will still set level with only about a 1/8 inch difference in height from front to rear.

4. The stock XLR overall wheel/tire combination diameter is approximately 27.25 inches. With your 26.50 inches in the rear, the speeedometer and odometer will be only be off by about 3%.

captam

NicklZ:

Correction to my above comment: The front to rear height differential will be approximately 3/8 inch.

capt am

Here's a couple of calculators that may help.

Wheel offset:

http://www.1010tires.com/WheelOffsetCalculator.asp

and tire size:

http://www.miata.net/garage/tirecalc.html


Might help. Chad

Our guide recommends the following offsets for the width wheels you are looking at.

(information based on a 2006 XLR

8.5 wide 43-65mm offset
10 wide 62-65mm offset

*lower offsets push the wheel out, higher offsets tuck the wheel in more.

Staying within these ranges should minimize any rubbing that you may have.

Recommended tire sizes 245/40-20 Front, 275/35-20 Rear

What is the width of the stock rim? Are our tires the widest that can go on those rims? The only changing I would like to do, if possible a wider tire on the car.

Standard XLR's come with 18x8 wheels with a 61mm offset and 235/50-18 tires.

Without upgrading your wheels it will be difficult to put on a larger/ wider tire. Depending on the tire you select, some modifications may be required.

Good advice, they don't have the clearance for wider tires.
BobStandard XLR's come with 18x8 wheels with a 61mm offset and 235/50-18 tires.

Without upgrading your wheels it will be difficult to put on a larger/ wider tire. Depending on the tire you select, some modifications may be required.