For '84, more power, luxury, and class

With Detroit-built car sales up sharply over a year ago, and with optimism high among automakers, the 1984 new-model caravan rolls into town. Motorists ask: Will it be the year of the rubber-burning performance car, the convertible, or the smaller car?

For the American automobile industry as well as the car buyer, the answer is ''all three.'' Instead of an uncompromising move to fuel economy, smallness, or front-wheel drive, the domestic companies are moving in several directions all at once.

First, consumers have grown weary of the gutless, poor-performing cars of the last few years. In response, carmakers are adding more zip under the hood for ' 84. To get the extra bang, they're adding turbo chargers to an increasing number of small-size engines. Motorists now want to step on the ''power pedal'' and go. At the same time there is less consumer concern over mileage as fuel prices and availability remain stable.

Too, carmakers are fielding more sports models for 1984 than in a long time.

Second, the convertible automobile is back in force even though it never really did go out of style.

Launched by Chrysler Corporation some 18 months ago, the factory-sponsored ragtop is in the midst of a renaissance as Detroit car manufacturers follow in Chrysler's tracks with more and more open-to-the-wind cars. Even the General Motors Cadillac division, which a few years ago said the softtop would never return, brings back the open-top Eldorado for 1984.

And third, many cars, including the big Cadillacs, are getting smaller.

The 1984 full-size Cadillac, for example, will be compressed by some two feet. More than a foot will be lopped off Ford's Continental Mark VII. The new mini-vans from Chrysler Corporation, due to hit the showroom early in the new year, will fit into the family garage. And American Motors has reduced the girth of its big Jeeps, the Cherokee and Wagoneer.

While fuel economy is still a selling point, motorists want higher performance and a lot more fun in the cars they buy.

Where will it all end? Detroit executives aren't quite sure, but one thing they do know, they plan to meet the demands of the buyers wherever they lead.

Here's a rundown on what's new from Detroit for 1984: General Motors

Dwarfing most other news at GM is the plastic-bodied Pontiac Fiero sport coupe, acclaimed by the division as ''the first 2-seat, mid-engine car ever produced by an American manufacturer.'' Enthusiasm has been running rampant for more than a year for the on-again, off-again car, which finally has made it to market.

The base-model Fiero, with a 2.5-liter, 4-cylinder engine that sits behind the driver and passenger but forward of the rear axle, starts at $7,799. Pontiac also markets a new 2000 Sunbird turbo and HO Firebird.

Beyond that, and far behind schedule, GM still plans to change over its high-luxury Cadillac DeVille, Buick Electra, and Oldsmobile 98 to front-wheel drive. At one time the cars were supposed to be ready for launch this month, but now it'll probably be sometime after the first of the year. If they hit the road in April or May, they'll be '85-model cars, in all likelihood.

Oldsmobile division unveils a sporty Cutlass wagon, the Firenza ES, and the front-drive Toronado Caliente.

All car divisions but Cadillac unveil new midsize, front-drive wagons as well. Ford Motor Company

With a continuing emphasis on aerodynamic styling, Ford introduces the latest edition in its Continental Mark series, the Mark VII, 13 inches shorter, 350 pounds lighter, and 1.5 inches lower than the predecessor Mark VI. A point of departure is the car's European-style covered headlights, which required approval by the federal government before they could be used.

The new Mark, which follows in the tracks of the aerodynamic Thunderbird/Cougar and Tempo/Topaz, comes as a 2-door model alone.

Drag coefficient of the new Continental Mark VII is 0.38, lowest of any high-luxury car, according to Ford. Standard engine is a fuel-injected 5-liter V-8. Later in the model year a 2.4-liter turbocharged diesel will be available with a German-built 4-speed automatic overdrive transmission with lockup torque converter.

The Goodyear-developed air suspension, also used in the 1984 Continental, provides automatic three-way leveling for the luxurious Mark, no matter the weight. Whether the load is five passengers with luggage or a driver alone, the system adjusts the car's road clearance, both front and rear.

Ford Motor Company is emphasizing its new power-train components for '84, including the addition of two passenger-car diesel engines.

A high-performance Ford Mustang SVO (Special Vehicle Operations), including an intercooled version of the 2.3-liter turbo, hits the marketplace, plus the turbocharged 2-seater Ford EXP. The LN-7 is dropped and the bubble-back rear end moves over to the EXP.

Ford earlier in the year unveiled the new Ford Thunderbird/Mercury Cougar and Ford Tempo/Mercury Topaz, in addition to the downsized Ford Bronco II utility vehicle. Chrysler Corporation

The fact that Chrysler is back in business is no secret. With its $1.2 billion federal government-backed debt paid back and a five-year $8 billion new-model program right on track, Chrysler is focusing on the ''year of the product'' as its factories turn out the '84 lineup of cars.

The smartly revived carmaker is highlighting two sports cars, the hatchback Dodge Daytona and Chrysler Laser, both of which will offer an optional turbocharged version of the company's 2.2-liter 4-cylinder engine.

Then in January it will launch its so-called T-van, the Dodge Caravan and Plymouth Voyager, plus a commercial model called the Dodge Ram Van. The new mini-van will fit in an average-size garage - a nice plus, according to Chrysler. Prices will start at about $8,000, and the transmissions are either a three-speed automatic or a five-speed manual.

Chrysler also has high-performance versions of the Dodge Charger and Plymouth Turisco as well as the Rampage and Scamp, pickup derivatives.

Early in the new year the company will market a high-power turbocharged Omni GT that is fast. I know because I drove it a few weeks ago at the Carroll Shelby Performance Center in Santa Fe Springs, Calif., which the former race-car driver runs for Chrysler Corporation. A Mitsubishi-built turbocharged Colt also is on the road for '84.

Chrysler is selling its own version of the Mitsubishi Starion, which the Japanese carmaker is selling under its own banner in the United States. The Chrysler version is called the Conquest.

In thinning out its new-car offerings, Chrysler drops the luxurious but poor selling Imperial, plus the Cordoba and Mirada. American Motors/Renault

Trying to capitalize on the success of its joint AMC/Renault-derived Alliance , AMC launches the Alliance-spawned Encore. The new Encore shares a lot of components with the Alliance, although the rear-end treatment is clearly a departure. It comes in both 2-door and 4-door styles.

The long-running AMC Spirit and Concord are phased out while the French-built R-5, or LeCar in the United States, is not being imported for '84.

Smaller XJ-series Jeeps make their debuts under the Cherokee and Wagoneer banners. A 2.8-liter Chevrolet-built V-6 engine is an option to AMC's own 2.5 -liter, 4-cylinder power plant.

AMC has dropped the Jeep CJ-5 for 1984.