Don't call it a hybrid! The 2012 Buick Regal eAssist is a sedan with "light electrification technology," GM says.

Now that that question's settled, here's another: Is a 25 percent overall increase in fuel economy worth a 2-grand lighter wallet? That's the real question facing buyers of the 2012 Regal.

Offered in Base, Premium I and Premium II trim, Regal — also available with a turbo four, by the way — can be had with either a 182-hp, 2.4-liter four-cylinder or that same four-banger with eAssist technology. The "light electrification" eAssist model, which includes a very hybrid-like 115v lithium-ion battery pack and 11 kW electric motor, exacts a $2,000 premium over the standard 2.4.

No matter the engine, a six-speed automatic is standard in this front-driver.

According to the EPA, eAssist, compared to the conventional 2.4-liter powertrain, improves fuel economy by 32 percent in the city and 16 percent on the highway by availing itself of the assistance of the electric motor and battery pack. It also shuts off the gasoline engine at stops.

The result is EPA estimates of 25 city/36 hwy — notably better than the 19/31 of the standard Regal 2.4, but not in the same league as full hybrids.

The primary difference between this "light electrification technology," which most folks call a "mild" hybrid, and "full" hybrid competitors like the Lincoln MKZ and Lexus HS 250h is that full hybrids, for short distances, can run on pure electric power. Regal eAssist cannot. If it's moving, the gasoline engine is turning. When off at stops, in fact, the minute you take your foot off the brake the engine starts up.

For that reason, Regal eAssist, though handily beating the mpg of non-hybrid competitors like the Acura TSX and VW CC, does not approach the city fuel economy ratings of the MKZ hybrid (41) or the HS 250h (35). It does, however, equal the Lincoln's 36 hwy rating while beating the Lexus's highway rating by 2.

In addition, the Buick costs a heck of a lot less to buy — about $5,700 less than the Lincoln, and roughly eight grand less than the Lexus.

For the record, we registered 25 mpg in 250 miles of all-city driving, just as the EPA promised. Our highway experience — a round trip to Ste. Genevieve, Mo. — was not quite as happy. We got a still-respectable 33 mpg in those 120 miles, but not EPA's 36.

On the road, eAssist, thanks to a torque boost from its electric motor, feels peppy enough around town. Its zero-to-60 sprint of just over 8 seconds, though nothing to write home to mom about, is slightly quicker than that of a standard Regal 2.4.

The drive, save irritatingly small outside rearview mirrors, is enjoyable in a hushed cabin.

Beautifully styled, Regal has plenty of room up front, adequate in back. The trunk, however, shrinks from 14.2 cu. ft. in conventional models to 11.4 cubes in eAssist to accommodate the battery pack.

Still, lovely to see and thrifty to own, Regal eAssist, available with touch-screen navigation, is an intriguing choice for entry-level luxury hybrid buyers who want to spend less on gas — and less for the car.