“The Buick LaCrosse expands its technological credentials by adding eAssist light electrification for the 2018 model,” says Buick in the most vague way possible, meaning that one of their more popular cars now comes in a hybrid.
The term “light electrification” is a pretty good way to go, because although this is a hybrid, it’s not a full blown one like a Prius.
What Buick, a brand both beloved in America’s heartland and China, is doing with their electrified LaCrosse here is combining an electric motor with the crossover’s 2.5 liter four-cylinder engine to deliver “quiet, refined, and spirited efficient performance backed by the value and customer experience expected of Buick.” Okay, all good so far. Nothing wrong with adding some batteries and an electric motor or two (look at what happened when Ferrari did it), but how does this all play out in the LaCrosse?
Buick’s new eAssist system (yes, that’s how they spell it) pairs the four-cylinder engine with a compact lithium-ion battery pack to offer benefits usually found on fully electric vehicles. So the LaCrosse dials in such goodies as torque-assisted launch, energy-saving regenerative braking (which can also enhance braking performance), and an exceptionally smooth stop/start system. Buick loves this new eAssist system so much it will be the standard powertrain for the 2018 LaCrosse when it goes on sale this fall.
When installed in the LaCrosse, the eAssist differs from previous Buick eAssist implementations by being more sophisticated, powerful, and compact. It gives a 9 percent increase in overall torque, allowing drivers to get the responsiveness expected from a full-size sedan. Also, the newest eAssist system is noticeably smaller and unobtrusively packaged, so you still get to use the LaCrosse’s fold-down rear seat and abundant trunk space. Option-wise, the new standard 2.5 liter four-cylinder/eAssist drivetrain complements the popular V6 plant that remains untouched, and will still be available on select trims.
Other updates on the 2018 Buick LaCrosse include more packages with available all-wheel drive and an all-new nine-speed automatic transmission for the V6 models. By mid-2018, Buick will have five models available with the new advanced transmission. Customer demand is very high for Buick’s intelligent all-wheel drive and active twin clutch gearbox, so that will now be available on the Essence trim.
Now, the nitty-gritty, techno-details on this whole eAssist deal. The short version is that eAssist combines a compact electric motor powered by a 24-cell, air-cooled 0.45kWh lithium-ion battery pack with the 2.5-liter four-banger gas engine. This combo is designed to enhance efficiency and maintain refined performance.
All of this gets to the tarmac with five major components.
First, there’s the Motor Generator Unit or MGU. The MGU replaces the conventional alternator and acts as an electric motor to provide more power when needed. The MGU is also an electric generator that provides the energy stored in the lithium-ion battery pack. Next there is the entire Electric Assist scheme, the software controlling what switches on or off, and when. The MGU’s electric motor provides extra power for smooth launches while in the Auto-Stop mode. It also funnels additional torque to the engine when the Electric Assist wizards think it’s needed to optimize overall performance and efficiency.
With hybrid systems, there’s also some cool tricks you can do with the braking. In the case of the 2018 Buick LaCrosse, regenerative braking is part of the act. When you hit the brakes or start coasting, some of the energy you normally give away as heat is, in the case of the Buick, converted to electricity through the graces of the MGU and stored in the lithium-ion battery pack.
Speaking of that lithium-ion battery pack, in our case here, it’s an 86V unit, which has been revamped and repackaged to be more compact. It takes up less space, meaning more room for people and stuff. The energy kept waiting in the lithium-ion battery pack powers the electrical system when the entire vehicle it is in Auto-Stop mode. The lithium-ion battery pack also gets power to the MGU to help with the aforementioned smooth launch while in Auto-Stop mode, or additional torque to the engine as the ones and zeros see fit.
The stop/start technology contributes to added fuel savings by turning off the engine when you are in Auto-Stop mode. So, when you are at a stoplight or in heavy traffic, for example, the LaCrosse will shut off the four-banger, and run things on batteries alone. It will then restart the engine when your foot lifts off the brake pedal.
Aerodynamics & Availability
The 2018 Buick LaCrosse also gets a host of aero improvements to help with efficiency. There are upper and lower active aero shutters in the front fascia. These close under certain driving conditions to help maximize aerodynamics and contribute to improved fuel economy; e.g. when you’re going fast enough, they close, since enough air is getting forced over the radiator anyway. Buick makes no mention of cost, but that will most likely be revealed as we get closer to the fall release date of the 2018 LaCrosse.
Tony Borroz has spent his entire life racing antique and sports cars. He means well, even if he has a bias towards lighter, agile cars rather than big engine muscle cars or family sedans.