From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Comparison of the performance of Isotta, Bentley, Vauxhall, and Sunbeam cars against the Phantom model.
| Identifier | ExFiles\Box 4\8\ 08-page32 | |
| Date | 1st January 1928 guessed | |
| contd :- -2- ISOTTA. This is the only car directly comparable with the 'Phantom' for size. We believe that there are Phantom cars running today equipped with comfortable sports bodies and lamps, wings etc. which will surpass the performance of the Isotta in every particular when arranged as a normal touring car. We are quite certain that the Isotta in full touring trim with wheels and lamps cannot lap Brooklands at 90 m.p.h. against the watch. Their speedometers are open to suspicion. BENTLEY. This is a much smaller car. We should say that the standard 3-litre can lap Brooklands at about 85 m.p.h. in full touring trim. The acceleration is relatively poor for a super-sports car being about the same as a Phantom with a sports body. 30/98 VAUXHALL. Much the best acceleration and maximum speed of any standard sports car as it has a 4½ litre engine to the Bentley and Sunbeam 3 litre while carrying the same sort of body. This car should be able to lap Brooklands in full touring trim at 90 m.p.h. but it is doubtful if it can sustain continued all-out running without constant attention. SUNBEAM. Much the same performance as the Bentley with slightly greater maximum speed. All these cars be it noted, in spite of being specifically designed for speed, have a lap speed on Brooklands in full touring trim of 90 m.p.h. or less as you will be able to confirm yourself. Remove the wings, lamps, windscreen etc. and the result may be very different - but what is the use of that to an ordinary owner? contd :- | ||