The Lamborghini Countach LP500S model, or 5000S as it became know in the United States, was intorduced at the '82 Geneva Motor Show. About 321 cars were built between 1982 and 1985. Designed by Gandini, the cars featured a tubular spaceframe chassis clad in thin aluminum panels. Pirelli developed a special P7 series rear tire for the Countach in 335-50-15 size to match the new OZ aluminum 13x15 wheels that had replaced the Campagnolo magnesium wheels used previously on the LP400S model. The six-Weber carburetor 4754cc engine produced 400 bhp at 7,000 rpm. Production pf the Countach series ceased in 1990.