You should be able to back up your boasts.

Take, Porsche, for example, which not so modestly claims that its new 911 turbo coupe grips the pavement, "like peanut butter to the roof of your mouth" and provides a driving experience equal to "owning your own amusement park."

Heady stuff-and after test driving the machine, we'd have to concede that every word is true.

In case you are one of those who has spent the last few years driving at 54 miles per hour in the center lane of the expressway, you may have failed to notice that Porsche redesigned and re-engineered its 911 series last fall as 1995 models and, in April, added the 911 turbo for good measure, as a 1996 model.

The turbo is powered by the same 3.6-liter, 6-cylinder engine offered in the regular 911 coupe, except that it adds twin turbos to boost the horsepower from the healthy 270 to 400 get-up-and-go-without-any-whoa horses. And you don't have to wait very long for the turbos to kick in.

Slip into the leather bucket seat, fasten the harness, turn the key, which is in an unusual position at the left of the wheel, and step on the pedal.

Your head snaps back as the upper torso is slammed into the seat. The body-both yours and the car's-seem to rise from the pavement in preparation for liftoff. It's a rush.

We tossed the coins in the basket at the tollway entrance ramp and when the light turned green kicked the pedal. The speedometer soon read 80 m.p.h., and we were still only halfway down the ramp headed for the straightaway and had gone through only half of the gears in the 6-speed manual that propels this machine.

The911 turbo is the fastest street legal Porsche made, the only twin turbo all-wheel-drive sport coupe sold in the U.S., and a car with a singular purpose, according to its keeper, Fred Schwab, president of Porsche Cars of North America:

"We took everything we are good at and put it into one package with the 911 turbo," Schwab told us in a brief stopover to deliver the chariot.

Porsche is to sports cars as Jaguar is to luxury sedans: a machine that everyone craves to experience, if only once; a four-wheel image maker and status symbol; a 400-h.p. amusement park.

Fast, to be sure. And sure-footed. The 911 turbo is an all-wheel-drive Carrera 4 with an attitude-in addition to decorative and distinctive fender flares, rocker panel extensions, whale tail rear spoiler and a pair of air-intake ports along the grille to make it distinct from the Carrera 4.

With all-wheel-drive the vehicle is nimble and lateral movement is precise. You dart into and out of corners or passing lanes. Also contributing to above-average handling are force-sensitive power steering (more assist at low speeds, less at high speeds) and a limited slip differential with automatic brake differential traction control, a somewhat high-tech-sounding name for a system that transfers power to the front wheels when the rear ones start to slip and automatically pulses the brakes to transfer power from any slipping wheel to one that isn't to maintain traction.

The turbo also features stabilizer bars, fully independent suspension and 18-inch speed-rated tires. It should be noted that while the turbo coupe clings like the above-noted peanut butter, it's far more user-friendly on non-blemished surfaces than on trails under construction or ones lined with thick bands of crack-sealing tar. If the pavement isn't smooth, you may start to wonder whether Porsche makes buckboards, too.

Noteworthy features include dual air bags, a 25 percent reduction in pedal effort with the clutch; larger brakes with anti-lock, which means that while the car can sprint from 0- to 60-m.p.h. in 4.4 seconds, the action can be reversed in only 2.6 seconds; an ignition that becomes disabled and won't start if you open a door and don't administer the key within 18 seconds of shutting that door (unless you press a button on the key fob); and a new gas discharge headlamp bulb that not only is 2 1/2 times brighter than traditional bulbs, but also burns with a bluish gray tint to provide a more natural light to reduce eye fatigue when traveling long distances.

On the minus side, as the old expression goes, you'll pass everything on the road except gas stations. The 13-mile-per-gallon city/19-m.p.g. highway rating carries a $2,600 gas-guzzler tax. The tank holds 19.4 gallons, though after a couple of days of driving you start to suspect that it's not a gas tank but an evaporation canister holding the fuel. Get a gasoline credit card. Get two.

The rear seats serve but one useful purpose: they keep the 911 turbo from being rated as a two-seater for insurance purposes. Adults won't fit in back, even kids need be masters of yoga to make an attempt.

The 911 turbo would make a most attractive convertible, but that's out of the question, Schwab says, because the 400-h.p. engine has so much power that removing the roof would remove the structural foundation and integrity for the body that goes with it.

Saving the best for last, the 1996 911 turbo starts at $99,000, to which you need add only $2,600 for the guzzler tax and $745 in freight for the complete package. The only option you'll need is a stick to beat the folks away from your car.

>> 1996 Porsche 911 Targa Wheelbase: 89.5 inches Length: 167.8 inches Engine: 3.6-liter, 282-h.p., 6-cylinder Transmission: Tiptronic with dual automatic/clutchless manual modes. EPA mileage: 17 m.p.g. city/24 m.p.g. highway Base price: $74,015. Price as tested: $76,763. Includes $1,036 for turquoise metallic paint, $110 for floor mats, $315 for radio upgrade with compact-disc player, $930 for sound upgrade with 10 speakers and $357 for rear-window wiper. Add $745 for freight. Pluses: Potent machine yet as comfortable as your typical luxury sedan. Excellent ride and handling. Car sits flat in aggressive maneuvering for the feeling of driver control. Distinctive and appealing styling. Minuses: Glass Targa top plays havoc with your rear vision when retracted a little or a lot. >>