General Motors will introduce a new dual clutch all wheel drive system built by British supplier GKN Driveline on the new 2017 Buick LaCrosse. The system adds two electronically controlled clutches to the rear axle in place of the traditional mechanical differential. The arrangements lets the car’s onboard computer determine how much, if any, of the engine’s power is transmitted to each rear wheel.
“This has a real performance element to it, with big benefits on acceleration and cornering,” LaCrosse Marketing Manager Doug Osterhoff said in a recent interview. “We think this will have more play” in warm weather states where consumers traditionally are less interested in all wheel drive systems. Less than 10% of buyers opt for the mechanical awd system on the LaCrosse today.
The electronic dual clutch enables what is known today as “torque vectoring” — a way to not only send power to a wheel with traction but also enhance cornering ability by delivering more power to the outside wheel, which helps the car turn. Torque vectoring is becoming a popular concept in cars with electric drivetrains, like the proposed Honda CR-Z with 4 electric motors that is said to be in the works.
The ability to seamlessly shift torque between the rear wheels offers improved ride and handling compared to traditional all wheel drive systems, says Ray Kuczera, GKN’s vice president of global product technology. The two clutch setup is similar to the GKN systems used on the Range Rover Evoque crossover and the Ford Focus RS, according to Automotive News.
“Customers are seeing all wheel drive as more than just a go anywhere traction feature,” Kuczera said. “The two-clutch system can also influence the vehicle dynamics and improve the feeling of the car when you’re going straight or turning. It’s more nuanced vehicle control.”
The GKN system will be featured on Cadillac’s newest SUV, the XT5, that goes on sale next spring, but with an added benefit. It will be able to disconnect the rear wheels entirely in certain circumstances to boost fuel economy on the open road. “As OEMs get more and more worried about saving fuel, having these twin clutches is the most efficient way to disconnect the rear” while still being able to offer all wheel drive to customers who need it, Kuczera says.The GKN system is expected to be available on other GM products with all wheel drive in the years to come.
Photo credit: Automotive News