TOKYO - This year's Tokyo auto show proves to be a strange contradiction.

At one end are the Japanese domestic automakers, all showing advanced technology geared toward realizing more ecologically friendly production cars. Foreign automakers, meanwhile, seem bent on stealing the show with enormous, swoopy concept cars and high-horsepower engines. The two camps could not have been more diametrically - or environmentally - opposed.

Some speculate that the overwhelming number of "environmentally correct" vehicles displayed by the Japanese automakers here is largely posturing in preparation for the highly anticipated global warming conference to be held in Japan this month. Other critics believe Japan's domestic automakers are merely attempting to spin environmental friendliness into a new, large-scale marketing "theme" to stoke the country's stagnant auto market.

Although the answer may be found in equal portions of several explanations, what cannot be discounted is that many of the vehicles and technologies on display here are quite real and production-ready.

Toyota Motor Corp., for example, displays its Prius hybrid electric vehicle (HEV), which is scheduled to be available for public consumption beginning next month. It is the world's first production HEV.

The MR-S sports car is a light, minimalist 2-seater notable mainly for carrying the company's 1.8L I-4 with variable valve timing. Toyota recently announced that the 1.8L engine, on which the MR-S's engine is based, is the powerplant several speculative reports earlier this year said would have one-third fewer parts and be extremely lightweight. As it turns out, the DOHC 1.8L has roughly 25% fewer parts - a total of just 560 in all.

Economy-minded concepts aren't the only thing on Toyota's mind. The NC250, while sporting bodywork only the Japanese market could love, is in reality the company's long-ballyhooed rival for the BMW 3 Series. The NC250 employs a front-mounted 2.5L 6-cyl. driving the rear wheels, while its proportions practically mirror those of the 3 Series. It is not known if Toyota will export a version of this car, but English-language markings provide a clue that it will.

With the Grand Cruiser, Toyota also previews the upcoming redesign of its popular Land Cruiser. Apart from its enormous proportions is a new, 4.7L V-8 developing 311 ft.-lbs. (422 Nm) of torque; optional will be an all-new 4.2L direct-injection (DI) 6-cyl. turbodiesel.

Mazda Motor Corp. for the first time publicly unveils its heralded replacement for the MX-5 Miata - the wait, however, disappoints many critics, as the car is only mildly restyled and employs carryover engines. The platform for the next - and all-new - Miata may serve, however, as the basis for a rear-drive compact sedan to battle Toyota's NC250 and a similar car Honda Motor Co. Ltd. reportedly plans.

Apart from a host of new minicars and minivans, highlighted by the production-ready R'nessa, Nissan Motor Co. Ltd. displays a spate of eco-efficient technology, spearheaded by several new continuously variable transmissions (CVTs). The company shows a new-generation CVT said to be of a particularly low-friction design and a CVT that operates as an automatic transmission or can be shifted sequentially through a set of five fixed ratios. The sequentially shifted CVT was fitted to the Stylish 6 (based on the Cefiro/Maxima sedan/wagon), a gasoline/electric hybrid with a 2.5L VQ DOHC V-6/electric traction motor combo that Nissan says will result in a 50% fuel-economy boost over a conventionally powered V-6 Cefiro.

Nissan also displays the AL-X, an all-aluminum concept car with a parallel-hybrid drivetrain and CVT.

Honda, not to be left behind by its domestic rivals, unveils several unique eco-friendly concepts, as well as its ZLEV gasoline engine.

Honda's four concept vehicles are shown under the coding of "J-Movers": the J-MW, a tiny minivan with a 1.5L I-4 engine and Honda's CVT, which is dubbed Honda Multi Matic; the J-MJ, a sport/utility vehicle (SUV)/minivan with the same drivetrain as the J-MW but with Honda's new Dual Pump System (DPS) all-wheel drive; the J-WJ, a station wagon/SUV; and the J-VX, Honda's interpretation of a low-polluting sports car, fitted with a 1L 3-cyl. engine featuring the company's VTEC variable valve timing system and an electric-assist traction motor - as well as a sequentially shiftable CVT.

Honda's J-VX with its 1L engine is an example of the numerous small-displacement, high-specific-output engines touted by the Japanese carmakers. Mitsubishi Motors Corp. shows a 1.1L version of its highly publicized GDI (gasoline direct injection) family, powering its "box on wheels" Maia concept.

But perhaps the most intriguing of these small, economy-focused engines comes from Suzuki Motors Corp.: a 1.8L twin-turbocharged DOHC V-8. Suzuki says the all-aluminum V-8, shown in the shapely C2 roadster, develops more than 240 hp and approximately 200 ft.-lbs. (271 Nm) of torque from just 1.8L. Britain's Lotus Cars and France's Renault SA reportedly are both keenly interested in this powerplant for use in their Elise and Spider roadsters, respectively.

Nissan has plans to enter the DI race started by Mitsubishi and Toyota; the company releases details of its so-called Neo (Nissan Ecology Oriented) DI engines that encompass both gasoline and diesel DI powerplants. Nissan says these next-generation DI engines will be produced as two variants of its inline 6-cyl. engine range and two inline 4-cyl. units.

The importers, meanwhile, take an almost completely different tack, featuring high-horsepower concepts and production cars with proportions decidedly at odds with most of what the Japanese automakers are pushing. The spiritual leader of this group is the Mercedes-Benz Maybach, a gargantuan, 139-in. (352-cm) wheelbase limousine concept that Mercedes appears serious about building. The Maybach's engine is an all-aluminum derivation of the longstand-ing Mercedes 6L V-12, complete with a cylinder-cutoff feature that allows the engine to cruise in 8-cyl. or even 6-cyl. mode.

The American automak-ers show up with big-engined production cars destined for the Japanese market. General Motors Corp.'s Cadillac division unveils a right-hand drive (RHD) version of its 1998 Seville, the first RHD Cadillac sent to Japan since 1941. The Seville will be exported to Japan with the same 4.6L DOHC V-8 found in U.S.-market versions, but front and rear fascias have been revised to bring the car to the 5-meter overall length critical in Japan. Chrysler Corp. plans to send its Viper roadster/coupe to Japan for 1998, complete with its hulking 8L V-10 OHV engine.

Perhaps the show's largest surprise comes from BMW AG and its curvaceous Z07 roadster. The Z07 is speculated to presage the coupe/convertible replacement for BMW's current 8 Series coupe. What isn't known at this time is how much of the Z07's aluminum space-frame chassis and mostly aluminum bodywork would end up in a production version.

The Z07's drivetrain, however, is a known quantity: the 4L, 400-hp DOHC V-8 BMW recently unveiled for the M5 sedan. BMW says the car's unique platform does borrow from current models, however. The front suspension is the mostly aluminum com-ponentry from the current 5-series, and the complex multilink rear suspension is lifted from the 7 Series.

And Volkswagen AG shows off its stunning midengined supercar, dubbed W12, whose primary reason for being is to showcase the company's new, technically intriguing 12-cyl. engine. The W12 uses the 12-cyl. engine installed longitudinally to drive all four wheels. VW likely won't ever produce a road-ready version of the supercar, but may produce a Le Mans-entry race car to put the new 12-cyl. engine to the endurance test.

- Peter Robinson and Giancarlo Perini, with Bill Visnic