[7] W. O. Bentley combined one of his road tests of the "Sun" with a trip to see the 1924 French Grand Prix in Lyon.

[12] In base form, with a single Smiths 5-jet carburettor,[1] twin ignition magnetos,[1][8][9] and a compression ratio of 4.4:1, the Bentley 6½ Litre delivered 147 horsepower (110 kW) at 3500 RPM.

[citation needed] By operating a patented compensating device, the driver could adjust all four brakes to correct for wear while the car was moving, which was particularly advantageous during races.

[12] With a single-port block, two SU carburettors,[5][8][11] a high-performance camshaft,[14] and a compression ratio of 5.3:1, the Speed Six's engine produced 180 hp (130 kW) at 3500 rpm.

[6] The Criminal Investigation Department of the Western Australia Police operated two saloon-bodied examples as patrol cars.

[15][16] The racing version of the Speed Six had a wheelbase of 11 feet (132 in; 3,353 mm)[5] and an engine with a compression ratio of 6.1:1 that produced 200 hp (150 kW) at 3500 rpm.