At the upcoming Chicago Auto Show, General Motors Co. will unveil a Buick Regal that features the e-Assist hybrid system. This will only be the second time that this technology will be applied after the ’12 Buick LaCrosse that’s expected to arrive in dealer showrooms this summer. Sources say that the Regal hybrid go into production by the end of August.
It was over a year ago that the report on the new mild hybrid system for the Regal first came out. With the e-Assist, the LaCrosse’s fuel economy will improve by 25% from 19-30 mpg (12.4-7.8 L/100 km) city/highway to 25-37 mpg (9.4-6.4 L/100 km).
Sources say that the Regal will get a similar boost as standard models of both cars with a 2.4L 4-cyl. engine and 6-speed transmission offer the same fuel economy rating. But the difference is that LaCrosse will have this hybrid system as its base powertrain but GM won’t do the same for the Regal.
GM insiders reveal that this is a “cost issue.” Product development of the e-Assist was delayed when GM entered bankruptcy. But currently, the e-Assist is expected to have a key role in meeting new U.S. fuel-economy regulations. It’s also expected to migrate to additional models in the near future.
During a briefing on e-Assist before the LaCrosse hybrid’s Los Angeles auto show debut in November, Steve Poulos, global chief engineer-eAssist at GM, said that this is the “base powertrain of the future.”
Steve Poulos, global chief engineer of the eAssist system, remarked that technology has the ability to provide an electric boost to the powertrain system during heavy acceleration and grade driving, thereby allowing both the engine and the transmission to operate in a more efficient manner.
He remarked that electric boost and regenerative braking are further complemented by full fuel shutoff during stops and deceleration, resulting to more fuel savings. Moreover, Regal with eAssist technology boasts of enhanced underbody aerodynamics and tires that have been optimized for performance and fuel efficiency.
Likewise, the vehicle comes with a hill-assist system that captures brake pressure to allow drivers to better accelerate from a standstill on a moderate or steep grade. This system achieves this by reducing the vehicle’s tendency to roll backward when the engine is in shut-down mode.
The eAssist system comes with a 115V air-cooled lithium-ion battery that adds around 11 kW (15 hp) of electric power assist during heavy acceleration and around 15 kW of regenerative braking power.
This eAssist system could compel the 2.4L Ecotec four-cylinder engine to shut down fuel delivery in specific deceleration conditions, thereby helping save more fuel. When in fuel shut-off mode, the induction motor-generator unit will still spin along with the engine, thereby delivering instant yet smooth acceleration power when the driver steps on the gas.
When the vehicle comes to a halt, the induction motor-generator unit spins the engine to bring it to a smooth stop. Regal’s compact and lightweight eAssist power pack (65 lbs) – which includes lithium-ion battery pack, an integrated power inverter and 12V power supply – is placed in a compartment between the rear seat and trunk.
It’s surprisingly compact and lightweight. While this reduces truck room a bit compared to MY2011 version with the four-cylinder/six-speed powertrain, it still offers 11.1 cubic feet (314 liters) of storage.
The power pack is cooled by a quiet electric fan that draws air from a vent located in the tray just behind the rear seat. Poulos remarked that the battery system is made to deliver power assistance to the internal combustion engine, instead of storing energy for all-electric propulsion, thereby making it an extension of the conventional engine.