The P5 appeared in September 1958,[3] badged as the "3-litre". It was powered by a 2,995-cubic-centimetre (182.8 cu in) engine. This straight-6 IOE engine used an overhead intake valve and side exhaust valve, an unusual arrangement inherited from the Rover P4. In this form, output of 115 brake horsepower (86 kW) was claimed.[3] An automatic transmission, overdrive on the manual, and Burman power steering were optional with overdrive becoming standard from May 1960. Stopping power came originally from a Girling brake system that employed 11-inch (280 mm) drums all round,[3] but this was a heavy car and by the time of the London Motor Show in October 1959 Girling front power discs brakes were fitted.[3] The suspension was independent at the front using wishbones and torsion bars and at the rear had a live axle with semi-elliptic leaf springs.