Use less fuel in city driving

Given that expecting motorists to manually start and stop their cars at traffic lights is impractical and unlikely to be widely adopted …

How can we stop our cars burning petrol while

  • waiting for a traffic light to go green
  • crawling in city traffic at less than 10km/h


  • Fit cars with a controller that will automatically stop the engine when travelling at less than 10km/h and start it again when either the car is accelerating through 10km/h or when the battery power is about to be exhausted.
  • Fit cars with batteries and electric motors that will start the car moving and drive the car up to 10km/h.
  • Assume the cars have an automatic transmission and front wheel drive.

How it would work

  • Waiting at a traffic light, the engine has been automatically switched off.
  • When the light goes green and the accelerator pedal is pressed, the electric motors move the car forward while the engine is started.
  • Once the engine is running, it takes over accelerating the car past 10km/h.


  • The batteries and motors can be much smaller than those required for fully hybrid drive.
  • Cars could be retrofitted with this technology. A small battery pack in the boot (truck) and the rear wheels replaced with wheels with integrated motors and regenerative brakes for recharging the batteries.

What do you think?

Speak Your Mind