I've been driving another supercharged Buick this past week and once again I'm moved to wonder why all manufacturers don't bolt blowers onto their otherwise modest V6 engines, converting them into covert Cobras, Trans Ams in disguise.

A good analogy of what the supercharger does for the 1998 Buick Regal GS can be found in Robert Louis Stevenson's tale of Dr. Jekyll and Mr. Hyde.By day, Dr. Regal is a solid citizen who quietly goes about his business. He allows fellow motorists to pull out in front of him, he always slows for pedestrians, he never violates traffic laws and he uses no more than his share of the world's hydrocarbon reserves (17 miles per gallon in city driving and 27 highway).

He is stylish but not flashy. He is neither the top of the Buick line nor the bottom. He has all the creature comforts - including heated leather seats, CD player and on-board computer - that someone of his social position could desire while eschewing ostentation and luxury for its own sake.

Ah, but then there is his alter ego. When the sun goes down - or whenever the mood strikes - Dr. Regal need but sip from the supercharger and he is instantly transformed into Mr. GS, a rowdy extrovert who can leave pony cars gaping at the stoplights, pass triple-trailer trucks in a single bound and make kids in hot rods gasp "Who was that guy?."

It's heady stuff, and all the more so because the car is so stealthy. There are no trunk-mounted spoilers on the supercharged Regal. No ground effects packages, no screaming eagle decals, no hood bulges. Just those two discreet letters, GS, give any clue that this Buick is but a foot-mash away from liftoff.

The standard Regal LS 3.8 liter V6 is good for 160 horsepower. The supercharged Regal GS churns out 240 ponies. Any questions?

Don't confuse supercharging with turbocharging. Turbochargers work off the engine exhaust and thus lag behind until the revs build up, but superchargers do their huffing and puffing right now!

The Regal got a complete new do last year, and my hat's off to the folks in Flint (Mich.) It's a winner. With a base price of $23,690 it offers a lot of value when put up against "near luxury" cars costing $10,000 more.

My test car's bottom line was $26,325, including $225 for heat-ed driver and passenger seats (worth every penny on those cold winter mornings); $650 for 16-inch chrome aluminum wheels (I'd also check that box on the order form), and what may be the biggest bargain in all of autodom, a $915 "prestige package" that includes dual AC, automatic climate control, a very nice dual CD/cassette sound system with controls on the steering wheel, six-way power driver and passenger seats, an auto-dimming rear view mirror, leather seats and metallic paint.

Some Honda models require you spend more than $915 just for air conditioning.

Style-wise, the new Regal is a looker; sporty but in a conservative, European way. The gray body cladding along the sides was first introduced by Mercedes-Benz but it works very well on the Buick and it nicely complemented my test car's red pearl paint.

Buick's designers also did a good job on the inside, although I had a few complaints regarding its ergonomics. For example, the buttons on the steering wheel that control the sound system are raised too high. At least a dozen times I inadvertently changed stations or raised the volume to ear-splitting levels.

In the same vein, the dual cupholder mounted in the center console was prone to leaping out whenever my right hand would brush it - very annoying.

And while the seats looked good, they were too soft, offering little lumbar or side support, and the leather was way slippery. In hard cornering, the car held its line just fine, but I was sliding all over the place.

Speaking of handling, it was good but nothing that will cause the engineers at BMW any sleepless nights. Still, when I think of how Buicks used to wallow down the road . . . you've come a long way, Baby.

For the 1998 model year, Buick has lowered the force of its air bags, a reaction to children and small adults being killed by exploding passenger bags. Also, a fuel vapor recovery system is now in place and an OnStar navigation system is an option, although my test car didn't have it.

Bottom line: The new Buick Regal GS offers a very high standard of luxury in a car costing thousands less than its competitors and tens of thousands less that cars offering similar performance.

There may be a downside to supercharging that I haven't heard about - maybe they have maintenance problems or wear out quickly - but until I know for sure, it strikes me as the Next Big Thing.