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BMW i8 plugin hybrid integrates GKN electric drive on front axles BMW North America
<p><strong>BMW i8 plug-in hybrid integrates GKN electric drive on front axles. </strong></p>

Electric Axle Business Spinning Up for GKN

As automakers maximize the potential of vehicle platforms, a GKN executive says the electric rear axle is a simple way to convert a front-drive architecture to a fuel-saving hybrid that also enables AWD when necessary.

AUBURN HILLS, MI – The growing popularity of all-wheel drive, especially in northern climates, has been well documented, which is good news for GKN and other axle suppliers.

But another trend, the electrified rear axle which can turn an AWD vehicle into a hybrid, has driveline producers gearing up, literally, for what they anticipate will be booming business.

U.K.-based GKN supplies the rear axle with an integrated electric motor for the new Volvo XC90 hybrid, which goes on sale in the U.S. this fall. The eye-catching Porsche 918 Spyder and BMW i8 plug-in hybrids integrate GKN electric drives on the front axles. In Europe, the supplier provides the Peugeot 3008 HYbrid4’s electrified axle.

GKN considers itself the market leader as well as the segment’s pioneer, having delivered more than 300,000 “M-4WD” e-axles for Nissan and Mazda hybrids sold in Japan since 2002.

Within 10 years, 30% of AWD systems in the U.S. will be electrified, the supplier estimates.

“We see it as a big trend in the auto industry,” Ray Kuczera, GKN Driveline’s vice president-product technology, tells WardsAuto during the dedication of GKN Automotive’s new North American headquarters here. “We are bidding on several other types of axles as well for other OEMs.”

As automakers attempt to combine and maximize the potential of vehicle platforms, Kuczera says the electric rear axle is a simple way to convert a front-drive architecture to a fuel-saving hybrid that also enables AWD when necessary.

“This allows them to use the bones of an existing platform and add an electric rear axle drive without a giant tear-up and really get a lot of benefits and the safety and security of AWD,” he says.

Kuczera says most automakers are interested in one electric motor mounted to an axle to power both wheels, but the short-lived Fisker Karma PHEV was one of the few vehicles integrating an electric motor for each of the rear wheels.

Le Mans Racecars Leverage Electric Axles

Nudging this segment along in the U.S. is the ubiquitous FWD CUV, whose popularity grows in tandem with that of AWD. WardsAuto data shows 55.4% of light trucks (including CUVs, SUVs, pickups and minivans) were equipped with AWD or 4WD last year, up from 47.2% in 2009.

Looking forward, North America will remain the No.1 market for AWD. IHS Automotive forecasts a 21% increase in AWD systems by 2020, reaching 3 million vehicles annually.

Reinforcing the trend toward electrified axles is the arrival of hybrid-electric exotic cars such as the Ferrari LaFerrari, 918 Spyder and Lamborghini Asterion concept, all with electrically driven axles that will help these automakers meet increasingly stringent CAFE requirements in the coming years.

On the marketing front, it helps that prototype racecars with hybrid drivetrains have been victorious at the grueling 24 Hours of Le Mans. Porsche won this year with the 919 Hybrid after Audi won several previous races.

Audi is carrying its e-Tron success from the racetrack to the factory as the electrified A3 e-Tron Sportback is on sale now and headed to the U.S. in the fall. Audi also unveiled the Q7 e-Tron 3.0 TDI quattro at this year’s Geneva auto show, but production has not yet been confirmed.

The auto industry is extremely interested in filtering electrified axles to non-luxury mainstream vehicles because the cost premium is not exorbitant, says Bob Willig, GKN Driveline’s president-Americas.

Bob Willig, GKN Driveline’s president-Americas, speaks at Auburn Hills dedication.

“It depends on the region,” he says. “Obviously in Europe there’s a higher cost for fuel, so we see a high degree of interest there.”

GKN does not build motors but sources them from other producers, sometimes at the direction of the OEM customer, Willig says. GKN integrates the motor into the axle assembly and develops the necessary software and controls.

For the i8, BMW wanted a front axle that could run in hybrid mode even at maximum speed.

“To do it, we had to have two speeds,” Kuczera says. With the second speed, the drivetrain can function with a smaller motor and battery pack, while achieving a 15% efficiency gain.

“BMW is trying to find that balance between a realistic car to drive and a supercar,” he says. “They went with the 2-speed and went with the efficiency gains.”

Growth in Disconnecting Axles, Too

As suppliers such as GKN, Magna, ZF and American Axle continue developing expertise with electric axles, Kuczera expects automakers will hand over more drivetrain responsibility. Many hybrids today house electric motors within the transmission, but he sees good reasons to integrate them instead within the axle housings.

“We are trying to get everything now into one package space, to downsize everything to make it so it’s optimal instead of having two different cooling circuits,” Kuczera says. “GKN has that unique experience, bringing the other components together and simplifying things for the OEMs.”

Even without an element of electrification, GKN and other axle suppliers see opportunities with disconnecting AWD systems that boost fuel efficiency by cutting off torque to the rear wheels when it’s not needed.

GKN supplies such a system for the Jeep Renegade and its platform mate, the Fiat 500X, as well as the Range Rover Evoque. American Axle supplies a similar system for the Jeep Cherokee.

GKN’s Steve LaChance (left) and Ray Kuczera see opportunities with disconnecting drivelines, such as this one supplied for Jeep Renegade.

Kuczera says the technology makes a bigger difference on the highway, when the rear axle can be disconnected for long stretches, reducing fuel consumption by 1 mpg (0.4 km/L).

Mike Manley, president and CEO of the Jeep Brand, says he is thrilled with the disconnecting drivelines offered in the Renegade and Cherokee, and he expects to see other potential Jeep applications in the future.

“The fuel-economy difference between the 4x2 and the 4x4 has narrowed significantly because of the use of that technology,” Manley tells journalists at a recent Fiat Chrysler event at the automaker’s proving grounds in Chelsea, MI.

Through the first half of the ’15 model year, 69% of Cherokees have been built with AWD, integrating the disconnecting driveline, according to WardsAuto data. Manley says he expects the mix of AWD Cherokees could go as high as 80% by year’s end.

As for electrified axles, Manley says they could fit well within Jeeps, “so long as they bring a benefit” and reinforce the brand’s rugged identity.

The volume of AWD and 4WD systems will continue climbing because they are becoming more affordable. Brian Maxim, vice president-global powertrain for AutoForecast Solutions, says vehicle prices have risen steadily for several years while the cost to consumers of AWD/4WD has remained relatively stable.

“This makes adding AWD as an option a smaller percentage of the purchase price and an easier cost for the consumer to accept,” Maxim says. “Many consumers like having the capabilities of AWD.”

Some 390 employees, including 200 engineers, have been moving to GKN’s new headquarters here since last fall from other facilities nearby in Auburn Hills and Sterling Heights.

GKN has several plants in North Carolina, Ohio and Mexico making differentials, drive shafts, half shafts, constant-velocity joints and other geared products. All of the facilities are running three shifts daily, plus frequent overtime on Saturdays.

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