Following the introduction of the E36 M3, racing teams in the United States began pressuring BMW for a homologation version in order to compete in sports-car racing. As a result, the 'M3 Lightweight' was introduced in 1995. The cars came without a radio (although the speakers were installed and the car pre-wired for the radio), air conditioning, leather seats, tool kit or a sunroof. The doors have aluminium skins. There is no underbonnet insulation blanket, and the boot only has carpet on the floor. The under body insulation is thinner and there is special carpeting to lower weight. Overall the changes resulted in a weight less than a regular M3. The wheels are 17 inches in diameter, with a width of 7.5 inches at the front and 8.5 inches at the rear. The tyres fitted were 235/40ZR17.