From 1988 to 1993, a special high performance XJS Series II, known as the XJR-S, was equipped with the 5.3 litres (5,344 cc) HE V12 engine and was produced by the newly formed JaguarSport, a separate company owned in a ratio of 50:50 by Jaguar and TWR Group Limited specialising in developing high performance Jaguar sports cars. After September 1989, the displacement of the engine was increased to 5,993 cc (6.0 L) and it was now equipped witb with Zytek fuel injection and engine management system. This was different from the standard 6.0-litre engine used in the late XJS models and was unique to this model. The car had a distinctive body kit, special alloy wheels, a unique suspension system utilising modified coil springs and Bilstein shocks, a luxurious interior with Connolly Autolux leather along with walnut wood trim, and handling improvements.