The system, known as Flywheel KERS (Kinetic Energy Recovery System), is fitted to a vehicle’s rear axle and stores energy captured during braking, a concept related to regenerative braking common in many hybrids. Those braking forces get the flywheel spinning at up to 60,000 revs per minute. Once the car starts to move again, the energy from the flywheel is transferred to a unique transmission that boosts acceleration form a stop – which requires a large amount of power and therefore gas – or it can be used during cruising to boost mpg. KERS is also currently used in top-tier auto racing. KERS is a light, cheap and very eco-efficient solution. It gives 25 percent better fuel economy.
The test vehicle was an S60, its ICE driving the front wheels while the KERS was attached to the rear axle. Under braking, the four-cylinder engine is shut off and the KERS gathers rotational energy, spinning at up to 60,000 revolutions per minute. The stored energy is then used to get the car going again or to assist at cruising speeds.
Like the units in Formula One, it provides an additional 80 horsepower. When working with the four-cylinder ICE, the S60 with KERS can do the 0-62 mph dash in 5.5 seconds, a full 1.1 seconds faster than the S60 with the 3.0-liter T6 engine and all-wheel drive.