Volvo S60 KERS Hybrid Prototype: Brief First Drive

Follow Nikki

Volvo S60 KERS Engineering Prototype

Volvo S60 KERS Engineering Prototype

Enlarge Photo

Can you really improve fuel economy and performance just by taking a production car with a turbocharged 5-cylinder engine and adding Formula 1 race technology? 

To find out, we headed to Volvo headquarters in Gothenburg, Sweden to test-drive a top-secret prototype Volvo has been testing for the past year.

It's an ordinary-looking 2013 Volvo S60 sedan with an 80-horsepower Kinetic Energy Recovery System (KERS) bolted to the rear axle. 

The Basics

Unlike the regenerative braking found on cars with start-stop, hybrid or all-electric drivetrains, KERS is an entirely mechanical system which bleeds off the car’s kinetic energy under braking, transferring it through a continuously variable transmission and storing it as mechanical energy in a vacuum-encased carbon-fiber flywheel.

As a consequence, a car with a KERS system does not require a heavy-duty alternator or motor, complex power electronics or additional batteries.

Instead, the flywheel stores the mechanical energy for up to 30 minutes, releasing it when required to aid in acceleration. 

Behind the wheel

Approaching Volvo’s one-of-a-kind prototype, there’s a noticeable whine from the S60’s trunk as its flywheel spins with energy from the previous test drive.

That’s due to a lack of sound insulation, says Volvo. Being an engineering prototype and proof-of-concept vehicle, it’s a little rough and ready around the edges. 

Inside the cockpit, too, some obvious giveaways remind us we’re sitting in an engineering mule. Alongside the standard S60 dash, there’s a tablet PC mounted to the dash, displaying KERS status information, and the obligatory red emergency disconnect switch required of all prototype vehicles. 

To start with, our chaperone disengages KERS completely, so as to remind us of the stock performance of Volvo’s usual 2.5-liter Turbocharged five-cylinder engine. Accelerating quickly onto the test track thanks to 254 horsepower and 266 foot-pounds of torque at the front wheels, there’s nothing strange or unusual about driving this car. 

Volvo S60 KERS Engineering Prototype

Volvo S60 KERS Engineering Prototype

Enlarge Photo

Then KERS is switched on and placed into ‘hybrid’ mode, we enter head for a tight corner, and start slowing down. 

Somewhere behind the rear seat, we hear the sound of a jet engine crossed with a laser rifle and quickly realize KERS is spinning its flywheel up to an electronically-limited 60,000 rpm top speed. The sound is intoxicating, and a quick glance at the KERS system display tells us we’re recapturing somewhere around 30 kW of instantaneous power.

Exiting the curve and heading for a reasonably steep incline, we accelerate and notice the S60’s engine doesn’t roar as much as it did on entering the track. This time, KERS is doing some of the work and the gasoline engine is noticeably less strained. 

Cresting the hill and passing down the other side, we notice the T5 engine has completely switched off, coasting down toward the next corner. At low speeds, and when there’s enough stored energy, the prototype creeps along using just the flywheel-stored energy to move it along, starting the engine when more power is needed. 

Switch into ‘Sport’ mode, and KERS acts a little like a boost function, storing energy when the car is cruising as well as braking to release it under heavy acceleration. 

The result, Volvo says, is a 0-62mph time of 5.5 seconds, 1.5 seconds faster than the stock S60 T5. While Volvo’s tiny test track didn’t afford us much chance to test this, we can say the extra 80 horsepower boost from the KERS system gave the well-built Swede a sportier feel.

Meanwhile, the high-pitched whine as the KERS system charged up, combined with the way it pushed us into our seats every time it discharged encouraged us to squeeze the throttle to the floor at every apex, however short the straight.

Follow Us

Commenting is closed for this article

Take Us With You!


© 2018 Green Car Reports. All Rights Reserved. Green Car Reports is published by Internet Brands Automotive Group. Stock photography by izmostock. Read our Cookie Policy.