Bentley & Rolls Royce

Complete Overdrive Systems are readily available for:

  • 20 hp Rolls-Royce
  • 20/25 Rolls-Royce
  • 25/30 Rolls-Royce
  • Phantom II
  • Phantom III
  • 3 1/2 Derby Bentley
  • 4 1/4 Derby Bentley
  • 3 litre W.O.Bentley
  • 4 1/2 Litre W.O.Bentley
  • Speed Six


Fitting an overdrive to your classic car gives immediate benefits in terms of reduced engine & transmission wear and enhances the pleasure of driving.

For a given engine speed the Overdrive will, theoretically, give an extra 28% road speed. So that:-

Direct drive 3000 rpm 60 mph
Overdrive 3000 rpm 77 mph

While many of these older cars have the power and torque to do this, it is very important to consider beforehand how you are going to get rid of this extra speed in a hurry when you need to!

Probably of more interest is that for a given road speed, the Overdrive will drop the engine revs by 22%, so that:-

Direct drive 60 mph 3000 rpm
Overdrive 60 mph 2350 rpm

Overdrives can be fitted to many other vehicles. Our policy is to tailor make the overdrive to fit your car, not to try and make your car fit our overdrive.