One of the automotive success stories of the mid-'80s has to be the Hyundai, the Korean-manufactured economy car that set sales records only shortly after the first car was sold in February 1986.

Hyundai Motor Co. was fortunate enough to be in the right place at the right time.

It introduced its car when most manufacturers were upscaling and the true economy car was being ignored. There's not a lot of money to be made on bare-bones low-priced cars, and many buyers weren't really interested in them. But through a clever advertising campaign (Cars That Make Sense), an attractive price and low-cost labor, Hyundai brought in a winner.

And it was not just because the car was priced at the lower end of the price scale - there are other low-priced cars, too - but it offered a car with a long list of standard equipment at a competitive price. Sort of like an upscale economy car but at the base price.

The test car (supplied by Chris Koch Hyundai, Emmaus) was an Excel GL four-door sedan. In the order of Excels, the GL is a step above the base Excel and below the better-equipped GLS. There is also a sporty GS model. The GL four-door sedan (it is also available in three-door and five-door hatchback versions) is a nicely equipped and appointed little car.

Although essentially a Japanese car built in Korea, the Excel has an international look to it. And little wonder, since it was designed by the master himself, Giorgetto Giugiaro of the Ital Design Studio. The overall appearance is smooth, clean and subtly aerodynamic. The test car was especially cheerful looking with its bright blue paint (named ice blue) and red body side stripe within a black molding.

The design can even be more appreciated when one realizes how small this car is. The sedan has a wheelbase of 93.7 inches, length of 168 inches (the hatchbacks are seven inches shorter), width of 63.1 inches, height of 54.1 inches and curb weight of 2,156 pounds. With an interior volume index of 93 cubic feet (82 passenger/11 cargo), it is classed as a subcompact (between 85 and 99 cubic feet).

The car is rated for five passengers and, if the front seats aren't extended fully aft and the back seat passengers are on the small side, it could very well be. Front-seat leg room is listed at 40.9 inches and should be sufficient for most drivers. However, for the very tall, it will be tight. At 11 cubic feet, the trunk isn't exceptionally large. It is nicely laid out with the spare below a flat floor and is fully carpeted.

The test car was equipped with the standard five-speed manual transmission (a three-speed automatic is available as an option), so a knowledge of clutching and shifting is required. The transmission, however, is not that difficult to use (the small engine doesn't necessitate a heavy clutch) and is suitable for a beginner.

The short wheelbase, four-wheel independent suspension (MacPhers on struts up front, trailing arms with coil springs in the rear and stabilizer bars on both ends) and all-season radials (Goodyear P155/80R-13) combine for decent handling. It is no sports sedan, nor does Hyundai claim it to be, but it is nimble and easy to drive and park. Although the test car did not have the optional power steering, it was a snap to turn.

Instruments and controls are easy to interpret and use. Nothing in the least tricky or difficult. But then there really isn't much there. The really impressive item is the large analog quartz clock with a number for every hour. The face is about the size of a standard alarm clock. No doubt it can take a licking and keep on ticking.

A small economy car should have a small engine, so there are no surprises under the hood. Nestled transversely in this front-wheel-drive car is a 1.5- liter/91-cubic-inch four-cylinder engine. It features an overhead cam and two-barrel carburetor with electronic feedbacka d is rated at 68 horsepower at 5,500 rpm and 82 foot pounds torque at 3,500 rpm.

The engine ran smoothly for the most part: there was no stumbling or stalling, but once in awhile a slight hesitation could be felt. I assume this was the electronic feedback hunting for peak fuel economy.

Although 68 horses wouldn't last long at the drag strip, they are enough to move a 2,156-pound car around with ease. Performance isn't overwhelming but it is more than sufficient for all Lehigh Valley driving conditions. Keep in mind, though, the Excel is an economy car and this is what it does best. The test car averaged 35 miles per gallon over the highway and 23 mpg in city driving - all on unleaded regular.

Base price on the GL sedan is $7,149 and, as mentioned frequently, there was a good deal of standard equipment. In addition to items already mentioned there were power brakes, body-color 5-MPH bumpers, halogen headlamps, front and rear mud flaps, rear-window defroster, cargo area light, locking fuel filler door, variable intermittent wipers, graphic display, rear seat heater ducts, dual remote control rearview mirrors, tinted glass, remote trunk release and full center console.

Test-car options were an electronically tuned AM/FM stereo cassette with dual speakers, $295, and air conditioning, $735. With an inland freight and handling charge of $275, the final line came to $8,454. The car is protected by a three-year/36,000-mile ''bumper-to-bumper'' new-vehicle warranty and a 36-month/no mileage limitation corrosion perforation warranty.

Right now things are slow in new-car sales, and Hyundai is feeling the squeeze. So the company, which broke sales records in the beginning, is now forced to give rebates. This may be tough on the manufacturer but certainly good news to the consumer. Nothing is offered on the base Excel, but there's a $600 rebate on the GL and $1,000 on all GLS and GS models.