Starting this summer, Buick will offer the 4-cylinder LaCrosse sedan with the eAssist micro-hybrid technology as standard. The LaCrosse eAssist uses a variety of systems and body modifications to deliver an estimated fuel economy rating of 37 mpg on the highway and 25 mpg in the city (pending EPA certification).
Mated to a 182HP 2.4-liter Ecotec direct injection 4-cylinder engine and a six-speed automatic transmission, the eAssist system consists of a 115V lithium-ion battery and a 15kW electric motor/generator that enable regenerative braking each time the throttle pedal is released. The electricity produced powers all the electrical systems of the car in order to save fuel.
The eAssist also uses power stored in the battery to provide up to 15HP of electric power assistance in various driving scenarios. “The additional 15 hp provided by electric assist allowed us to lower LaCrosse’s gear ratio without sacrificing reserve acceleration and performance,” said Steve Poulos, global chief engineer of the eAssist system.
“For example, when climbing the grade of an overpass, a normal vehicle will downshift and lose some fuel efficiency, but LaCrosse with eAssist maintains gear for improved performance and increased efficiency,” Poulos added.
Another function of the eAssist system is the engine shut-off mode, which improves fuel economy by cutting fuel delivery in certain deceleration conditions. Other than the mechanical aspects, the LaCrosse with eAssist comes with improved underbody aerodynamics, low-resistance tyres and electronically controlled shutters in the lower grille that close at higher speeds to push more air over the car, thus increasing aerodynamic efficiency.
In order to motivate eco-driving, the car's instrument panel features an Eco gauge that shows the driver how to attain maximum efficiency. The eAssist system will also be available on the Buick Regal in late 2011. Check out the video below to get a better understanding of how the system works.
By Dan Mihalascu
_______________________________________________________________________
