The major distinction between the LS and GS lies under the hood. Both use GM's ubiquitous 3800 Series II V6, a 3.8-liter unit originally developed by Buick. In the LS, this engine is naturally aspirated. That's an exotic-sounding term which simply means that it breathes the way most engines do, relying on the motion of the pistons to draw in air at atmospheric pressure. In that form, it is rated 195 horsepower and 220 pounds-feet of torque.

The GS is motivated by the same basic engine, but fitted with a supercharger. That's another exotic-sounding term, one that means, essentially, air pump. The supercharger pumps in more air than the engine would naturally draw, boosting horsepower to 240 and torque to 280 pounds-feet.

Both engines drive the front wheels through a four-speed automatic transmission, although the GS has a heavy-duty unit to handle the extra torque. Both LS and GS have ABS and traction control, but the GS gets a more sophisticated system. The LS system modulates engine power to reduce wheel spin under acceleration. The GS uses a full-range traction control system that can also selectively apply the brakes.

GS comes with a higher level of standard equipment, including a crisper Gran Touring suspension, 16-inch aluminum-alloy wheels with slightly more aggressive tires, and GM's OnStar communications system. You can add the GS wheel/tire/suspension upgrade to the LS for an even $600.

Last year, Buick offered a limited-production Olympic Edition Regal by designer Joseph Abboud. Its successor for 2002 is simply called the Abboud Regal, and features a dramatic two-toned leather interior, abounding in Abboud signature emblems. Exterior colors are limited to Dark Bronze Mist, White, Graphite Metallic, and Sterling Silver Metallic, all with Light Sandrift lower body panels. Abboud Regals all come with a sunroof, premium Monsoon stereo, and unique accents on the grille and wheels. The Abboud treatment adds $995 to the price of a Regal GS, but a hefty $3647 to a Regal LS, as in the latter case it also includes major luxury upgrades plus the GS tire and suspension package.