Lucas' L-Jetronic fuel injection system, using dual catalytic converters, using a modified exhaust manifold and adding antismog equipment. The engine's compression ratio was modified to 8.13:1. Beginning in the 1980 model year, the American version of the 3528 cc V8 used in the Triumph TR8 produced 133 hp with carburetors, except in California where it produced 137 hp with fuel injection. Beginning in June 1980, the American version of the Rover 3500 produced 148 hp with fuel injection, while the European version of the Rover SD1 produced 155 hp with carburetors. For the 1981 model year, both the Rover 3500 and Triumph TR8 produced 148 hp with fuel injection, and 1981 would be the last year for both models in the United States. Fuel injection for the 3528 cc V8 Rover engine was first introduced in the Triumph TR8 (137 hp) intended for California, and then introduced in the Rover 3500 (148 hp) later in the year when it was launched in America. Fuel injection for the Rover V8 was introduced in Europe, along with other modifications such as having a hotter camshaft, when the 1982 Rover SD1 Vitesse was launched with 192 hp. strike: [Publicity material claimed it was capable of reaching 148 hp (SAE) at 5100 rpm but the car as sold actually peaked at 133 hp (at 5000 rpm). ] Since August 1978, a carbureted engine, with antismog equipment, had already been on sale in Australia with . Beginning in the 1981 model year, Australia received a version of the fuel injected federalized engine with . Despite the necessary modifications, Rover chose not to set up an assembly plant in the US but built and shipped the cars from the Solihull factory. The SD1 gained positive reviews in the American press and was competitively priced against rivals such as the BMW 5 Series and corresponding Mercedes-Benzes. Nevertheless, the car achieved just 480 sales between its launch in June 1980 and the end of that year. The whole of 1981 attracted 774 sales, although most of these cars had actually been built and stockpiled the previous year. Rover ceased the supply of American market SD1s at the end of 1981, although unsold cars remained available from dealers well into the following year. Reasons for the commercial failure of the SD1 in the US are open to speculation. The weak value of the American dollar against European currencies at