Technical specialists retrofitted a MY2013 Ford Escape with Schaeffler technologies, and the payback is a double-digit-percentage fuel-economy improvement compared to the production SUV’s original mpg ratings.
“Our target in phase one was to get under $40 per percent of fuel-economy improvement and meet the 2020 CAFE (corporate average fuel economy) regulation requirements," Jeff Hemphill, Vice President and Chief Technology Officer for Schaeffler Group North America, told Automotive Engineering Jan. 13 at the 2014 North American International Auto Show in Detroit. "We almost exactly matched our initial simulation projections, which are more than a 15% improvement in fuel economy.”
Schaeffler’s SUV demonstrator has been accumulating real-world miles since September 2013. Fuel-economy improvements of more than 15% and CO2 emissions reductions of approximately 15% as determined by Schaeffler testing were later confirmed by an independent testing institute in Ohio, Hemphill said.
Powered by a 2.0-L EcoBoost four-cylinder mated to a six-speed automatic transmission, the demonstration 4WD SUV (known as the Efficient Future Mobility North America) received friction-reducing modifications to the belt drive, valvetrain, and balance shaft. It also was equipped with low-rolling-resistance tires and other fuel-conserving technologies.
A thermal-management module, similar to a Schaeffler unit used by Audi on certain production vehicles, enables the demonstration vehicle to reach optimal engine temperature quickly. The module also provides a precisely controlled temperature balance for other integrated components and delivers a 1% reduction in fuel consumption for city and highway driving.
Depending on the driving situation, Schaeffler’s North American-developed AWD disconnect clutch decouples the drivetrain from the rear axle at the power transfer unit (PTU). A second disconnection point in the rear axle prevents torque from being transferred by the rotating rear wheels to the drivetrain. Consisting of a hydraulically operated synchronizer clutch integrated in the PTU’s input shaft and electronically operated rear-axle dog clutches, the AWD disconnect clutch system can generate fuel savings of up to 2% in city driving and up to 6% in highway driving.
Schaeffler’s permanently engaged starter, which uses a wrap spring one-way clutch for connecting the starter to the torque converter’s housing, can provide up to 6% fuel savings in city traffic, Hemphill said. Complementing the stop-start system is Schaeffler’s latching valve, which stores hydraulic pressure to keep the transmission in first gear.
The AWD disconnect clutch, the permanently engaged starter, and the latching valve are all second-generation technologies that "will be production-ready for the 2017 model year," he noted.
The currently configured demonstration vehicle was designed to meet 2020 CAFE requirements without additional electrification of the powertrain. The same vehicle will undergo further modifications.
“Phase two has already started with a 48-volt mild hybrid system," said Hemphill. "There will be other technologies as well, but we haven’t determined the final package yet. The plan is to bring the vehicle in line with the 2025 CAFE requirements."