It's hard to nitpick Nissan's latest version of Z-car technology

Seizing the wheel of a new Nissan 300ZX sports coupe, I head into the homebound traffic, the sun soon dropping below the horizon of a late-November sky. The car is tight, pickup and steering quick, and the ride firm.

I smile: This really is a fun car to drive and one way to shorten the drive home, even if not the distance itself.

Soon my thoughts race back to the first time I met a Z-car.

It was November 1969. And the place? The ballroom of the Hotel Pierre in New York City. On display was a stunning new sports car from Nissan, an instant hit from Japan's No. 2 automaker. Introducing the Datsun 240Z for 1970 was the head of the Datsun organization in the United States, Yutaka Katayama.

Now Mr. Katayama is back in Japan, retired from Nissan, and the Datsun nameplate has been hung on the wall. Yet the Nissan Z-car itself is very much alive. If the 240Z was an instant success, so is the latest rendition of the Z, the 300 series ZX.

In design, the new ZX looks a lot like the car it replaces, the 280ZX, but there the similarity ends. The big difference is in the engineering and handling capability of the car.

The new ZX model rides on the same 91.3-inch wheelbase and has the same sweeping lines as its predecessor. Yet on closer look, it's a few inches shorter in length, thanks to the compact 3-liter V-6 engine instead of the longer 2.8 -liter ''straight-6.'' It also has a steeper rake to the windshield and peek-a-boo, semi-retractable headlights instead of the kind that sink fully into the front fenders when not in use.

While you probably would not notice, the new Z-car is an inch and a half wider than the 280 design, thus allowing a wider tread between both the front and rear wheels.

Curb weight of the base-model 300 is 2,888 pounds while the 2+2 checks the scales at 2,974 pounds, only slightly less than the 280ZX. Higher levels of sound insulation helped to stymie the weight-loss plans of the Japanese design crew.

Most people these days know something about coefficient of drag (Cd), a measurement of the ease with which a car slips through the air. At 0.31 (0.30 for the turbo), the wedge-shaped, aerodynamic 300ZX is moving into new low ground for a production car. The 280ZX had a Cd of 0.36, while the year-old Chevrolet Corvette is 0.34. A low Cd contributes to more road distance on a gallon of fuel.

The Environmental Protection Agency figures the 300ZX at 22 mpg in the city and 33 on the highway. Realistic figures may be somewhat less, however.

For the technologically inclined, the potent 60-degree fuel-injected V-6 engine is the first Japanese-built V-6 sold in the United States and includes a crossflow cylinder head and hydraulic valve lifters.

In normally aspirated form, the engine produces 160 hp, up from 145 hp for the straight-6 in the 280-ZX - more than enough for most people on the road, at least in the US. The turbocharged version of the V-6 yields an even 200 hp, compared to 180 for the inline ''6.'' The 300ZX can flash from 0 to 60 mph in 6. 3 seconds.

Two new automatic transmissions are available with the 300ZX, as well as a 5 -speed manual.

The Nissan Z-cars are test beds for advanced technology, Japanese-style. Five computers control the engine, transmission, audio, air conditioning, and theft-deterrent systems.

In driving the car, straight-line stability is flawless, and the wheels stay flat on the ground in a hard-cornering maneuver on the road. The easy-to-read instrumentation, night and day, keeps the driver fully informed, and all of the controls are easy to operate. There are even two trip odometers in the car - two , mind you - while the fuel gauge keeps a particularly close watch on the gas supply as the needle drops to the one-quarter-tank level.

The engineers paid a lot of attention to the suspension for a sporty, albeit comfortable, ride under almost any condition with which most motorists will ever be faced.

Along with its highly rated handling characteristics, the 300ZX is simply a nice car to drive, but so are many other sport coupes and sedans these days. There is, however, an aura about the Nissan Z-series, spurred in part by the right kind of marketing push, but also by what the car delivers to the motorist who buys one.

It should help recover some of the ground lost to the Toyota Supra, not to mention the Chevrolet Corvette.

Indeed, it's hard to nitpick this latest version of Z-car technology. Approaching motorists at night continually flash their high-beam lights at the Z-car, even though the headlights are on low beam. A slight adjustment in focus, I imagine. What else? It's hard to find anything.

The floor carpets haven't quite caught up to the 300ZX, being still marked, at least in this car, with the 280ZX brand mark.

The Z-car was designed specifically for the United States, and even today more than 90 percent of total Z-car output is shipped here.

The 1984 ZX comes in two body styles, a 2-seat fastback coupe and 2+2. The two-seater has a choice of either nonturbo power or the turbocharged GS. The base coupe lists for $15,799, with the turbo a couple of thousand dollars more. By comparison, the original Datsun 240-Z for 1970 went out the door for about $3 ,500, a surprise to anyone who saw it at the time. It shows what has happened to car prices in the last 14 years.

Sportiness has long been the hallmark of the Nissan Z-series cars, but the Z's also include many of the accoutrements of a high-level interior as well.

The newest member of the club is not a disappointment. If numbers have any meaning at all, Nissan has sold more than 725,000 Z-cars since the 240Z made its bow at New York's Hotel Pierre some 14 years ago.