to allow it to run on lower octane unleaded fuel. With the addition of a catalytic converter and exhaust gas recirculating system, the engine only delivered (DIN) with a slower 0–60 mph time of 16.3 seconds. The notable exception to this was the 1976 model year, where the compression ratio was raised to 9.1:1. This improvement was short-lived, however, as the ratio was again reduced to 7.5:1 for the remaining years of production. In the UK the 9:1 compression ratio, less restrictive emissions control equipment, and the Type HS2 SU carburettors now being replaced with larger Type HS4 models, led to the most powerful variant to date. The 1500 Spitfire now produced 71 hp (DIN) at 5,500 rpm, and produced of torque at 3,000 rpm. Top speed was now at the mark, and 0 to was reached in 13.2 seconds. Fuel economy was reduced to 29mpg. Further improvements to the suspension followed with the 1500 included longer swing axles and a lowered spring mounting point for more negative camber and a wider rear track. The wider, lower stance gave an impressive skid pad result of 0.87g average. The American market Spitfire 1500 is identified by large plastic over-riders and wing mounted reflectors on the front and back wings/fenders. US specification models up to 1978 featured chrome bumpers, and on the 1979 and 1980 models these were replaced by black rubber bumpers with built-in over-riders, using chassis extensions to support the bumpers. Detail improvements continued to be made throughout the 1500's production run, including reclining seats with "chequered brushed nylon centre panels" and head restraints, introduced for domestic market cars early in 1977 along with a new set of column stalk operated minor controls (as fitted already in the TR7) replacing the old dashboard mounted knobs and switches. Also added for the model's final years were a wood dash, hazard flashers and an electric screen washer, in place of the previous manual pump operated ones. Options such as the hard top, tonneau cover, map light and overdrive continued to be popular, but wire wheels ceased to be available. The 1980 model was the last and the heaviest Spitfire, weighing . Base prices for the 1980 model year were $7,365 in the US and £3,631 in the UK. Assembled at Canley in August 1980 shortly before the factory closed, the last Spitfire was an Inca Yellow UK-model including the factory hardtop and