Originally Posted by Toolman

Some of the standard Crossfire wheels have been known to crack. I would remove the wheel/tire from the car and spray soapy water everywhere to see bubbles to find the leak. Better yet, if you can find a container large enough to at least submerge a third or more of the tire and wheel into water will work even better. A bath tub would work for that, but make sure you protect the bottom and sides as the tire will mark it up and be hard to remove. Besides the cracks, which are rare, it could be the tire bead around the wheel is corroded, the valve stem is cracked, the valve itself could be leaking, and of course punctures in the tires.