2007 Lexus GS450h Road Test

Lexus will start selling its second hybrid vehicle in May, and this time its not all about fuel efficiency and clean air. This time the focus is on power.

The car is the GS450h, a two-ton, rear-wheel-drive, mid-size sport/luxury sedan which will blister the macadam from a dead stop to 60 mph in 5.2 seconds – enough to put this Lexus in a dead heat with a Porsche 911 equipped with an automatic transmission.

The GS450h will also keep pace with or outgun its V-8 powered rivals up to its governor-limited 131 mile-an-hour top speed, carve a cleaner path through the atmosphere and return up to 25 miles per gallon of premium fuel in the city and 28 on the highway.

That was the message from Bob Carter, Lexus Group vice president and general manager, as the GS450h and its more conventional relative, the entry-level ES350, were introduced to a group of automotive journalists during a press conference at the Ritz Carlton Hotel on Lake Las Vegas a resort community some 20 miles southeast of Nevadas gaming capital.

Labeling the newest hybrid the most technologically advanced production vehicle in the world, Carter ticked off these benchmarks: first truly high-performance hybrid . . . first rear-drive hybrid sedan . . . among the quickest Lexus vehicles ever built.

And, on the subject of mosts, the GS450h, with a base price of $54,900, replaces the V8-powered, $52,070 GS430 as the most expensive of the recently redesigned Lexus mid-sizers.

The principles that governed the engineering of the GS450h are not much different from those which underpin the entry-level Toyota Prius, but the execution required ground-breaking technology.

For this car, the engineers have combined a 3.5-liter V-6 engine, massaged to 292-horsepower, with a couple of powerful electric motors and a battery pack. One electric motor, rated at 197 horsepower, drives the rear wheels by itself or in tandem with the gasoline engine. It also helps to recharge the vehicles battery pack. The second, rated at 180 horsepower, functions as a starter for the gasoline engine and generates electricity for the batteries. Together, engine and motors deliver power equal to that of a 339- horsepower V-8.

That was the easy part. The real trick was to devise a transmission that could effectively deliver hybrid power to the rear wheels and build it to approximately the same size as a conventional six-speed automatic transmission.

It was accomplished in a way that will be understood best by those who know the meaning of Ravingeux gearset and planetary arrays. To the rest of us, it functions as a continuously variable transmission, which is to say that it can adjust gear ratios to all power requirements without the constraints of six predetermined speeds found in a conventional automatic shifter.

The car is awash in other technological innovations. They include an electric power steering system and air-conditioning compressor, eliminating the need for belts; an advanced stability control system that goes to work when it anticipates driver loss of control instead of after detecting it; electronically controlled brakes; and an optional suspension system which adjusts the front and rear sway bars to eliminate excessive body roll in turns.

While all of that is impressive, the ultimate concern to anyone thinking of purchasing a GS450h is how it rides and drives.

Despite limited time behind the wheel, driving partner Charles Ofria, major domo of this website, and I were able to get a pretty good sense of the car as we put it through its paces on some snaky stretches of two-lane macadam in the Lake Mead National Recreational Area.

Leadfoot Charlie, apparently determined to see if the car really had a 131-mph cutoff, beat a path to the Red Rocks area in what may have been the days record time. We experienced and re-experienced – the cars tremendous rush of acceleration, but the restrictions of two lanes and occasional lumbering recreational vehicles kept him a few miles per hour short of reaching the Lexus upper limits.

I the older, more mature, more sensible motorist – took a different approach on the return trip. I kept my top speed to a modest 105 mph and maintained a much more leisurely pace, say in the neighborhood of 80 to 90 mph.

From this exuberant test of Lexus hybrid hot rod we were able to make a few important determinations.

• It really can keep pace with the hottest of the competition.
• Even at seriously high speeds, it is incredibly smooth, quiet and stable. Our test drive probably sounds more exciting than it felt. When you have a car with sophisticated suspension, the visibility of desert terrain and a road surface with no pock marks, a constant 80 mph feels more like 50.
• Electric steering, sometimes numb and slow to react in other vehicles, was crisp and precise in the Lexus.
• The EPA estimate of fuel mileage is a real joke if you drive like Charlie. He averaged not quite 12 mpg during his stint behind the wheel. With somewhat less abuse of the accelerator, I brought the average mpg up to 22. The message here is that a driver might be able to approach the EPA estimates, but only if the exhilarating power is ignored in favor of posted speed limits.
• Those who need the aural stimulation of a traditional muscle car may have trouble getting used to the sound coming from the GS450h. Since there are no distinctive gears, it is more reminiscent of a motor boat under power or a turbo-prop plane accelerating for take-off.
• The tachometer was sacrificed for a power meter that measures electrical usage. A tach is really not necessary, since the automatic transmission regulates maximum allowable engine speed, but a car built for serious performance seems odd without one.

When we returned from our excursion, we determined one more thing a prospective buyer needs to know. The battery pack gobbles up trunk space, leaving a mere eight cubic feet for the owner’s stuff. There is enough room for two golf bags, but the space will never work for a vacationing family of four.
To be fair, Lexus has not positioned the GS450h as a mainstream car. Its real mission is to educate consumers that hybrid power can be more than just an exercise in fuel savings and reduced emissions. The premium brand of Japanese manufacturer Toyota has set its U.S. sales goal for the GS450h at a very modest 2,000 a year.

Still, Lexus estimates that, driven similarly to the V-8 sedan, the hybrid will save 200 gallons of fuel a year and, probably most important to many, over a 150,000-mile life expectancy it will release 17 tons less carbon dioxide into the air than its V-8 competition.

The guess here is that Lexus will find enough well-heeled buyers who want to indulge their slightly guilty pleasures with a relatively clear conscience.

Specifications