the original princess was powered by a 3.5-litre straight-six engine. this was enlarged to a 4.0-litre unit without further modifications. the princess was often built to order. customers could specify the colour required and a range of different setups were available. these included triple or single carburetors and twin or single exhaust systems. whilst the sportier multiple carb version performed better, it achieved only 12 to 14 mpg. the single carburetor version gave slightly better fuel consumption. performance was good for a car of its size, with a top speed of and acceleration 0 to 60 mph in 20 seconds.