Volvo is testing flywheel technology--being used in Formula One racing to give cars an extra boost--as a technology that could help cut fuel use in future cars by as much as 20 percent.
Flywheels recapture energy normally lost as heat during braking. That energy can then be used to help propel the car.
Volvo research fits a flywheel kinetic-energy-recovery system to a car's rear axle, while a conventional engine powers the front wheels.
The flywheel system's quick energy buildup and release would make it ideal for stop-and-go driving scenarios, Volvo says.
The flywheel is made from carbon fiber and spins in a vacuum at speeds up to 60,000 rpm. According to Volvo, that stored energy would make a four-cylinder-powered car feel a lot more like a six-cylinder.
Volvo said the flywheel technology is adaptable to a variety of vehicles. It said the system could reach showrooms within a few years if development continues smoothly. Volvo will start testing prototypes on public roads in the third quarter.