Chicago 2011: 2012 Buick Regal eAssist live in the Windy City

We received the first details about Buick's new Regal eAssist earlier today, but we've just returned from seeing the car in person before the Chicago Auto Show officially kicks off tomorrow. Visually, the more fuel-efficient Regal looks no different than the standard car, save the addition of eco-friendly 17-inch alloy wheels and low-rolling-resistance tires.

What's most important about this car is what's under the hood – a 15-kilowatt electric motor that offers 15 horsepower and 110 pound-feet of torque for initial acceleration thrust, matched with Buick's 2.4-liter direct-injected inline-four. Combine that with regenerative braking and a start/stop system for the engine, and the end result is a Regal that's capable of achieving 26 miles per gallon in the city and 37 mpg highway.

Buick's new eAssist system first debuted on the larger LaCrosse sedan, where it will serve as the base powertrain for 2012 model year vehicles. With the Regal, however, the eAssist model will slot just above the base 2.4-liter car and below the Regal Turbo, which uses the automaker's 220-horsepower 2.0-liter Ecotec inline-four. Pricing will be announced closer to the eAssist's official launch later this year.