GREEN MEANS GO; Lexus unleashes its most powerful hybrid yet.(News)

Byline: ROGER HART

Toyota plans to build only 6000 Lexus GS 450h sedans for sale worldwide with just 2000 slated for the United States, so the car won't significantly add to the company's global bottom line. But the newest hybrid in the Toyota family is far more significant to the company in other, more important ways.

The GS 450h is the first rear-drive hybrid sedan, and while you can't call it a test bed, it is full of technology that will play significant roles as Toyota and Lexus expand their hybrid model lineup. Until now the gas-electric hybrids from Toyota (and Honda and Ford) have been either fwd or awd. GM's "mild hybrid'' Chevrolet Silverado and GMC Sierra pickups are either rwd or 4wd.

The GS hybrid has the same exterior dimensions as the gasoline-only GS 300/ 430-only subtle badges on the rocker panels and on the rear fascia give away its identity. All of the hybrid stuff (the electric motors, batteries and controllers) adds 386 pounds to the car, which now weighs a hefty 4134 pounds. For enthusiasts, the power bonus from the hybrid driveline overcomes the weight penalty.

The car has three power sources: a 3.5-liter V6 with dual injection that makes 292 hp at 6400 rpm and 267 lb-ft at 4800 rpm; motor generator one, which is the primary generator, engine starter and controller of engine speed that makes 180 hp; and motor generator two, which drives the rear wheels, makes 197 hp, and is the main piece in the regenerative braking system. As we have learned with previous hybrids, you can't tally the total horsepower of all three to get a final number. Lexus says the total output of the system is 339 hp, which helps make the GS 450h one of the quickest cars Lexus has produced.

With the instant torque delivered from the electric motors, the GS 450h accelerates from 0 to 60 mph in 5.2 seconds. For comparison, the GS 430 needs 5.7 seconds to get to 60 mph.

Also impressive is the thrust from 30 to 50 mph, which takes just 2.7 seconds. Equally impressive is 40-to-80-mph acceleration and the 60-to-100-mph run where the acceleration pushes you in your seat. Top speed is 131 mph.