One of the first of the sporty/economy cars - a title that may sound like somewhat of a contradiction but is as good as any to describe a blend of car that is a couple of steps above an economy car but not quite a sports car - was the Toyota Celica. It was introduced in Japan in 1970 and made its way to the American market in the years that followed.

In those 16 years the Celica has advanced with technological changes but basically remains the small personal-type car in the Toyota lineup. And although it has received radical changes for the 1986 model year, it still remains a two-door available in either a liftback or coupe version, has its own distinct styling and looks like it will be just as popular as previous models.

The big change for '86 is that the Celica is now a front-wheel drive car, a move that may seem long overdue since just about every other sporty/economy car has this drive configuration. But since Toyota is Japan's largest automobile manufacturing company and has had the best selling imported passenger car in United States since 1975, why knock it?

The new Celica also has all-new aerodynamic styling, which is not only attractive but is responsible for a low 0.31 coefficient of drag, and a four- wheel independent suspension. Toyota has also adapted the American system of producing mild and wild versions of the same basic car by offering a more powerful engine, along with upgraded suspension, on its top-of-the-line Celica GT-S model.

The test car (supplied by J.H. Bennett, 2300 Hanover Ave., Allentown) was the milder GT Liftback version, a model that no doubt will appeal to the most buyers. It was stylish, easy to drive (it had a four-speed automatic), economical to run and - surprise, surprise - had plenty of room to even accommodate oversized drivers. The latter point was somewhat overlooked in earlier Celicas. This increase in front seat interior space was apparently made possible by having the engine mounted transversely, a common design practice in front-wheel drive cars. The new Celica also has a lower driving position that contributes to a more sporty feel. So it takes a little more effort to swing in and out. But this is what you are paying for.

Exterior dimensions on the liftback include a wheelbase of 99.4 inches, overall length of 171.9 inches, width of 67.3 inches and height of 49.8 inches. On the inside, head room measures 37.8 inches in front and 34 inches in the rear while leg room is a long 44.4 inches in front and a skimpy 27.9 inches in the rear. Obviously, back seat passenger room is limited. This, though, shouldn't be surprising for a small, two-door sporty car. The curb weight is 2,579 pounds.

In addition to ample head and leg room, the Celica also has a unique tilt/ telescoping steering wheel to make life just a little easier for the driver. (The telescoping feature is standard on the more expensive GT-S m odel and optional on the GT model.) The steering wheel has a ''memory'' that allows it to be tilted up for easier entering and exiting and, when the driver is seated, tilted back to the pre-set position. (American cars have had tilt wheels for many, many years but it is a relatively recent item on imports. Some imports have offered an adjustable steering column but, at best, this is just an expedient substitute.)

As mentioned, the test car was an easy car to drive. Just slip it in drive and away you go. The four-speed automatic overdrive transmission has a lockout button (on the shifting column) for overdrive. This means the car can be quickly shifted to third for either addition power or for more holdback on steep grades. When I first drove the test car I felt something was missing. I soon discovered it was ''torque steer,'' a common characteristic of front- wheel drive vehicles. Toyota has controlled torque steer on the Celica by using more rigid equal l ngth driveshaft design.

The new four wheel independent suspension features MacPherson struts with stabilizer bar and gas-filled shocks up front, and a dual-link strut system with stabilizer bar and gas-filled shocks in the rear.

The test car performed well under all Lehigh Valley driving conditions. It was far from the fastest car around but most drivers would be happy with the performance. Powering the test car was the standard single-overhead-cam 2- liter (121 cubic inch) four-cylinder engine. This engine features electronic fuel injection and is rated at 97 horsepower at 4,400 rpm and 118 foot pounds torque at 4,000 rpm. Fuel mileage was very good. The test car averaged 23 miles per gallon for city driving and 32 mpg over Lehigh Valley highways.

For those who really want to move out, the GT-S version has a new 2-liter, twin-cam, 16-valve engine that is rated at 135 horsepower at 6,000 rpm and 125 foot pounds torque at 4,800 rpm. According to Toyota, the 16-valve engine will take the Celica from 0-60 mph in 8.2 seconds. To handle the additional power, the GT-S has an upgraded suspension system and larger tires and wheels (205/ 60R14 steel-belted radials instead of 185/70RS13 radials) and four-wheel disc brakes (the GT has disc brakes up front and drums in the rear).

Base price for the Celica GT Liftback is $10,918. Standard equipment includes: automatic transmission, power brakes, power rack-and-pinion steering, reclining cloth bucket seats with memory and lumbar support, electronic AM-FM stereo radio, power antenna, dual electric mirrors, rear window defogger and tilt steering wheel with memory. Total price on the test car came to $12,879.90, not an astonishing sum of money in this day and age but enough to catch someone's attention. Celicas have never been inexpensive cars but they have retained good resale value. Other expenses included: delivery charge, $310; air conditioning, $705; cruise control/telescopic wheel, $235; rear window wiper/washer, $105; (the last four items were installed by Mid-Atlantic Toyota) undercoating, $149.95; carpet mats, $98; door edge protector, $59.95, and cassette player, $299.