I mounted some aftermarket wheels from my Honda FIT onto the c today. First, the wheels are 6.5x15" with an offset of 40mm. The combined weight of the wheel and a 195/60 tire was 36.5 lbs, some 4 pounds more than the stock c steel wheel and 175 tire. Bolt pattern is 4x100... the hub bore of the stock c wheel is 54.7mm vs 56 of the Honda. Mounted the wheels and checked for rubbing and/or touching by turning the steering wheel from lock to lock and I'm happy to report there were no issues with wheels/tires having interference with the chassis with these wheel and tire specs. I have a c3 and the steering is not the modified ratio that the c4 has so I was doing this test to see what problems would be encountered on a car not designed for the added width of the alloys. some shots with the wheels added and the tires in relation to the fender edges. ... and the difference from stock to aftermarket wheels. Car has a much more planted feel and drives better with the extra width and grip, but I can tell the extra weight in the acceleration. Plus, the 195 tires are 2/10" taller than the stock tires, which gears it a smidgen taller. I think a better tire for this car would be a 185/60, LRR.