Take a pick among General Motors’ line-up of auto brands when it comes to overall popularity and chances are you’d take a while before picking Buick among them. It’s not the most popular brand by any stretch of the imagination, but thanks to a rejuvenation, Buick->ke17 is looking like it’s going to be a major player in the mid-size luxury sedan with the 2012 Buick LaCrosse->ke1790.

Taking the reins from the previous LaCrosse model, the 2012 model looks to take the company to the next level with an all new eAssist system that Buick is proclaiming to improve fuel economy by 25 percent. What’s most impressive about the new LaCrosse is that despite the state-of-the-art system that’s been given to the vehicle, Buick is not giving it an added impetus – separate cost from the vehicle – but rather, is putting the eAssist system as a standard feature in all 2012 models of the LaCrosse.

That, in itself, says a lot about Buick and it’s latest mid-size luxury sedan.

Continued after the jump.

Exterior and Interior

Measuring 197 x 73.1 x 59.2 inches, the 2012 LaCrosse is a little bigger than the 2011 Lincoln MKZ with the interior having just about equal space between the two. The LaCrosse has a seating capacity of five people with the headroom measuring 38 inches in the front and 37.3 inches in the back. The legroom has 41.7 inches in the front and 40.5 inches in the rear. Shoulder room measures 57.4 inches in the front and 56 inches in the back while hip room measures 55.2 inches in the front and 53.9 inches in the rear. Another stark element that should be noted with the 2012 LaCrosse is the trunk space, which, is one of the things that’s been reduced from the 2011 model. By taking into account, the eAssist power pack takes up some space in the truck, reducing the space of storage to just about 10.9 cubic inches. Lastly, the 2012 LaCrosse will come with a set of 17-inch steel rims with P245/50R17 all-season blackwall tires.

Performance

The 2012 Buick LaCrosse's suspension is a MacPherson strut coil-over-spring; twin-tube dampers with gas-charged valving; hollow direct-acting stabilizer bar.

Beginning with the 2012 LaCrosse, Buick’s new fuel-saving technology, the eAssist System is poised to redefine fuel economy, paving the way for Buick to become a major player in their auto segment for years to come.

The eAssist system is a technology that allows fuel-saving and improves fuel efficiency, the eAssist system on the 2012 LaCrosse will give consumers a vehicle that not only provides the standard high-end luxury and cost-efficient value, but also a car that will completely reshape its market segment, through its class-leading highway fuel economy of 37 miles per gallon on the highway and 25 miles per gallon in the city.

So how does this the 2012 LaCrosse’s eAssist system work?

By using a state-of-the-art lithium-ion battery system and electric motor-generator, the eAssist system enables the car to perform a multitude of tasks, all of which leads to improving the LaCrosse’s fuel economy by an estimated 25 % compared to the 2011 version.

The vehicle’s eAssist system is mated to a 2.4-liter Ecotec direct injection four-cylinder engine with the Hydra-Matic 6T40 six-speed automatic transmission. Despite the system sharing the same basic belt-alternator-starter configuration of past BAS designs, the former delivers more than three times the power and is much more capable than the latter system.

Going back to the aforementioned connection, the eAssist system uses the power that’s stored in the car’s battery to supply the necessary electrical boost needed to perform optimally in a number of driving scenarios, thereby maximizing both the engine and the car’s transmission. The work being done by the 115 volt lithium-ion battery and the newest 15-kW motor-generator unit allows the car to do a number of things, to help increase fuel economy, which includes providing up to 11 kW of electric power assistance during acceleration and 15 kW of regenerative braking power as compared to the 2kW of power assist and 5 kW of regenerative power that the BAS system was capable of.

The system also automatically shuts off the engine anytime the vehicle is stopped thereby saving fuel that would have otherwise been used. During this time, the car’s motor generator unit continues to spin along with the engine, providing an immediate take-off power then the driver decides to move. As soon as the vehicle comes to a stop, the same motor-generator unit spins then engine, effectively bringing the car to a smooth stop and making it ready for an even smoother re-start.

The eAssist system also features a hill-assist system that significantly reduces the car’s tendency to roll backward when the engine is in its shutdown mode, allowing driver’s to accelerate more comfortably on roads that have steep inclines.

Models of the 2012 Buick LaCrosse with the eAssist technology also comes with an ECO gauge on the vehicle’s instrument panel that consistently responds to a driver’s driving behavior and makes the necessary actions to ensure that the driver enjoys a ride of pure efficiency.

All told, the eAssist power pack comes with the lithium-ion battery pack, an integrated power inverter, and a 12V power supply. The system can be found housed in a compartment just between the LaCrosse’s rear seat and trunk with an electric fan that cools it by drawing air from a vent located in the package tray just behind the rear seat. Weighing around 65 pounds, the system is light enough that it still allows access to the trunk through the split-folding rear seats. The downside, if you can handle it, is that the overall trunk space of the 2012 LaCrosse is slightly smaller, yet it still has enough space – 10.9 cubic feet worth of space – to fit large amounts of items inside it.

As for the eAssist system’s electric motor-generator, the item is mounted to the engine in the usual space reserved for the alternator, providing motor assist and electric-generating functions through an engine belt-drive system.

Pricing

The 2012 Buick LaCrosse, together with the eAssist system as standard equipment, is expected to be priced at somewhere around $30,000, which, if you factor in the car’s size, comfort, and state-of-the-art technology, is a pretty affordable prize for a car.

Competition

Since it belongs to an auto segment that doesn’t lack competitors, the 2012 Buick LaCrosse figures to have its work cut out for it, even if it comes with the new eAssist system. That’s just how the nature of the best works. That being said, the LaCrosse’s biggest competition figures to be the Acura TL->ke1831, the Lincoln MKZ->ke456, and the Lexus ES350->ke280.