Ford Motor Company has the lock on the best-performing production coupe for the money, the Mustang GT, so it is probably only logical that it is now offering the hottest sedan, and not only for the money but almost across the board.

Talk about big bang for the bucks, the '89 Taurus SHO will not only out- perform most of the expensive import sedans, but do it at a much lower price and without any apparent sacrifice of anything. Except, perhaps, the prestige (?) that goes with spending lots of money.

The SHO (Super High Output - what else) is an example of what American auto manufacturers have been excelling at for years: taking a regular production model and turning it into a performance/sporty model by using a more powerful engine, an upgraded suspension system and using more sporty interior/exterior trim. And, lately, doing it all much more tastefully.

The basis for the SHO is the popular Taurus. How popular, you may ask? Well, in 1987 (latest yearly figures) Taurus sales were 354,971, placing it second only to the Ford Escort in the United States. The Taurus is also the winner of nearly two dozen awards. Now awards should be viewed with a somewhat jaundiced eye, but nevertheless the car must be offering something to attract all this attention.

Most responsible for setting the SHO apart from the regular Taurus, and many other cars at that, is its very unique power plant. Ford didn't go to turbocharging or supercharging, with which it does have experience, but rather went the double-overhead-cam, four-valves-per-cylinder route. The route, though, was rather long; in fact, right to Japan.

Since the SHO will have somewhat of a limited production run - perhaps about 25,000 units for the year - Ford got together with Yamaha, a company with considerable expertise in high-performance motorcycle and automobile racing engines, to build the engine, which is not only a piece of impressive engineeringbut also attractive looking (in a hi-tech fashion) under the hood. (With this mixed heritage, maybe it should be called the SHO-gun.)

The engine began life as the Taurus's 3-liter/181-cubic-inch overhead valve V-6. But after all was said and all was done, about all that remained was the displacement. The 24-valve DOHC V-6 (as is stamped on the die-cast aluminum plenums) is rated at 220 horsepower at 6,000 rpm and 200 foot pounds torque at 4,800 rpm and is not only technically sophisticated but mean.

For those impressed by such figures, the test car consistently (and smoothly) went from zero to 60 mph in just a little over seven seconds. This would be good for a sports car. In a mid-size, 3,000 pound, front-wheel drive sedan, it is something to brag about. According to Ford, the SHO's zero-to-100 performance rivals the Mustang GT and it outperforms the GT from 100 to 140 MPH. I'll take Ford's word on this.

Four-valve-per-cylinder engines operate at high rpm to achieve their power but even too much of a good thing can be overdone. The SHO's engine is designed to wind up to 7,300 rpm. At that speed a ''rev limiter'' starts cutting out cylinders to hold everything steady at the 7,300 rpm. Right away you may think this is to prevent the driver from blowing out the engine. Not so, says Ford. The rpm limit is not to protect the engine but to protect against over-revving the accessory drive components, which have not had to handle that much rpm before. The engine itself has been tested to speeds greater than 8,500 rpm. So, I wonder who's going to be the first kid on the block to disconnect the rev limiter?

The SHO comes only equipped with a five-speed manual transmission, a factor that may limit sales somewhat. In this day and age, not many drivers like to shift for themselves. Nevertheless, for those who enjoy the challenge and meaningful relationship of a manual transmission, this one is a dandy. Treat it right(p oper clutching and shifting) and it will operate smoothly and positively while ripping up the competition.

Now, keeping 220 horsepower under control in a rear-drive car takes a bit of finesse. In a front-wheel drive car there could be problems with that old bugaboo ''torque steer.'' Ford, fortunately, managed to control this by making numerous adjustments in the SHO driveline, including the addition of an intermediate bearing support, as well as equal-length half-shafts. There's still some torque steer left but hold onto the wheel and it will track straight even under pedal-to-the-metal acceleration.

The chassis was also reworked on the SHO to keep the power under control and provide sport sedan handling. This included four-wheel disk brakes, a handling suspension system with increased diameter stabilizer bars, re-valved struts and increased-rate bushings, and 15-inch VR-rated performance tires on cast aluminum wheels. The test car conquered cloverleafs, curves, corners and country roads without considerable concentration.

At a quick glance, and maybe even a couple of long ones, the SHO looks similar to a regular Taurus - meaning it is aerodynamic and still somewhat futuristic-looking. But it has its own special look because of its unique front valance panel with integral fog lamps, and lower side cladding and wheel spats.

The interior also goes along with this performance theme with articulating front seats, a full-length console and a leather-wrapped steering wheel. It also has a unique performance instrument cluster featuring revised graphics, an 8,000 rpm tachometer and a 140-mph speedometer. The test car had the optional leather seat trim, which further frosted the funnel cake.

As far as the car itself, it has a wheelbase of 106 inches, length of 188.4 inches, width of 70.8 inches, height of 54.3 inches and curb weight of 2,901 pounds. It has six-passenger capability with a bench front seat, though the SHO is designed as a five-passenger car. With 100 cubic feet of interior room, all five passengers have plenty of room, and there is also room for their luggage in the 17-cubic-foot trunk.

The SHO comes as a fully equipped car and, in addition to its unique running gear and chassis, has such standard features as air conditioning, speed control, power door locks, light group, rear-window defroster, diagnostic alert lights, power side windows, electronic AM/FM stereo search radio with four speakers and tilt-steering column.

Base price for the car is $19,739 - as mentioned, not a bad price for what it offers. Options included the Preferred Equipment Package 211 (high level audio system, front and rear floor mats, illuminated entry system, autolamp system), $533; leather seat trim, $415; keyless entry system, $121; dual six- way power seat upgrade, $251; electronic climate control upgrade, $181, and power antenna, $76. Add a $450 destination charge a nd the full price came to $21,768.

The Taurus SHO is protected by a 6-year/60,000-mile warranty on major power train components and a 6-year/100,000-mile corrosion perforation warranty.