Toyota has once again redesigned its least expensive car sold in this country, bringing us a 1991 Tercel subcompact that is slightly larger and more powerful than its predecessor but just about as fuel-efficient.

The new Tercel traces Toyota's latest design theme made most evident by the restyling of its Celica sports coupe for 1990. Softly sculpted curves inside and out replace the comparatively angular lines of the previous generation Tercel, first seen for 1987.Toyota has managed to hold the line on the '91 Tercel's starting price from 1990. But at $6,488 for the two-door model, little more than base transportation is offered. Even a 4-speed manual transaxle is found in place of the now common 5-speed gearbox.

All Tercels get an improved version of the 12-valve, 1.5 liter four-cylinder engine used previously, with horsepower up by 5 percent to 82 at 5,200 rpm. A fully balanced crankshaft has been added to reduce vibration, and a new fuel injection design provides better acceleration.

Fuel consumption for the base Tercel with the 4-speed manual is 33 mpg city/37 mpg highway, up slightly from 1990. But other Tercels get between 1 mpg and 2 mpg less, with 5-speed models EPA-rated at 29 mpg city/35 mpg highway; automatic versions 26 mpg city/29 mpg highway.

The four-door Tercel DLX starts at $7,898, and is more in keeping with what buyers have come to expect from small cars, especially Toyotas. Fabric seats and a 5-speed manual transaxle are standard, though items like a rear defogger, power steering and tachometer are either extra-cost or not offered.

At the top is a new model called the Tercel LE sedan, which starts at $9,948 with an automatic. Unfortunately, it is a 3-speed version instead of a 4-speed automatic now offered in many other subcompact cars.

The LE also gets an upgraded interior with split-folding rear seats, as well as a rear defogger, radio, tinted glass and levers to open the fuel door and trunk from the driver's seat.

Toyota says a typically equipped Tercel should cost about $9,200. But an LE sedan evaluated for this review cost $11,553, counting the $275 destination fee and a short list of popular extras: air conditioning ($755), power steering ($250) and AM-FM stereo cassette ($270).

That gridlocks the new Tercel in the middle of a crowded, competitive market that includes the new Nissan Sentra, Ford Escort, Geo Metro and Hyundai Excel - plus a wide array of compact cars from all over the globe.

The Tercel's interior has a rounded dashboard with four large ball-socket vents across its face. A deeply recessed instrument panel houses not much more than a large speedmeter and needle pointers for the fuel level and engine temperature. The light and wiper switches are stalk-mounted and easy to use.

The front seats are comfortable and supportive. Occupants are secured by a manual lap belt and a shoulder belt attached to the door frame. This arrangement hampers exit and entry only slightly.

Its split-back rear seat accommodates two adults in relative comfort for such a small car, or may be folded flat for extra cargo space. Its 10.7 cubic foot trunk opens wide and has a low liftover height.

Those fond of doing their own underhood maintenance should be careful because the oil filter and spark plugs are close to the engine's exhaust manifold.

The 2,085-pound Tercel LE has a firm but not harsh ride for a car with a wheelbase measuring just 94 inches. Its solid twist beam rear axle soaks up bumps well, and handling and braking are well within accepted limits despite its wimpish tires, mounted on 13-inch rims.

But road and wind noise at 60-65 mph serve as constant reminders that the Tercel is still a small economy car, despite efforts to minimize those intrusions with narrower body gaps and a sandwich-type firewall insulation.

The Tercel's 12-valve engine was found to have adequate power under most conditions with the automatic gearbox and was not overly buzzy at freeway speeds.

In short, the 1991 Tercel is improved in most areas over the old model, following the typical evolution process seen in most cars.

But it breaks no new ground in terms of perceived value - something Japanese carmakers built their reputations on as they all but buried their domestic competition during the 1980s.

What we really have here is another pleasant, inoffensively styled small car, but one backed by the solid reputation of Toyota, which in itself is sure to please. Still, buyers are urged to carefully compare the Tercel with its competitors before deciding.

Toyota plans to sell about 130,000 to 140,000 Tercels a year, with over half of them expected to be four-door models.