Volvo Says New Kinetic Energy Recovery System to Save 25 Percent More Fuel Than an Engine of Similar Power

By Jacob Brown | April 25, 2013
Remember when we told you Volvo was planning on discontinuing its five- and six-cylinder engines in favor of four-cylinder engines and hybrids? Volvo obviously isn't messing around, releasing information about its new kinetic energy regeneration system (KERS) today that will be a central piece of engineering in its next-generation vehicles.
"The testing of this complete experimental system for kinetic energy recovery was carried out during 2012. The results show that this technology combined with a four-cylinder turbo engine has the potential to reduce fuel consumption by up to 25 percent compared with a six-cylinder turbo engine at a comparable performance level," says Derek Crabb, Vice President Powertrain Engineering at Volvo Car Group, in a statement. "Giving the driver an extra 80 horsepower, it makes a car with a four-cylinder engine accelerate like one with a six-cylinder unit."
The KERS will be hooked up to the rear axle, spinning up to 60,000 rpm to recapture electricity through braking and channel it back into the batteries. From there, the stored-up electricity can be brought back into an electric motor in the car's flywheel, which is sandwiched between the engine and its transmission, giving it a boost of power without having to use much gas. If Volvo's predictions are correct, we might be able to expect a 300-horsepower car capable of 23 mpg in the city and 32 mpg on the highway versus the current six-cylinder Volvo S60's 18 mpg city/25 mpg highway. With a lighter, more aerodynamic car to work with, it could reach even higher. "The flywheel's stored energy is sufficient to power the car for short periods. This has a major impact on fuel consumption. Our calculations indicate that it will be possible to turn off the combustion engine about half the time when driving according to the official New European Driving Cycle," says Crabb. Volvo's S60 experimental car fitted with the new powertrain can accelerate from 0 to 60 in 5.5 seconds, close to the heavier 325-horsepower Volvo S60 R-Design. Additionally, Volvo says the new flywheel allows the engine to have less internal friction because of its carbon fiber construction, weighing just 13 pounds. Pending Volvo's research goes off without a hitch, expect it to show up in the 2015 Volvo XC90 three-row crossover, followed by the S60 and every model in between, delivering power that was once thought of as V-8 levels with four-cylinder efficiency. Source: Volvo