Gas-electric Lexus SUV is quiet, zippy

By Ann M. Job

updated 9:19 a.m. ET March 11, 2005

The 2006 Lexus RX 400h rolling into showrooms next month isn’t just America's first luxury gas-electric hybrid vehicle.

Filled with soft, leather-trimmed seats, standard navigation system and rearview camera, the RX 400h is an experiment of sorts to see how many affluent car buyers, who usually don't make fuel economy a high priority, will want a high-tech hybrid sport utility vehicle.

Some affluent buyers “want to make a statement about their social consciousness ... that they care (about the world and the environment), but they want to do it without compromising,” said Denny Clements, group vice president and general manager for Lexus, a division of Toyota.

With a starting manufacturers suggested retail price, including destination charge, of $49,185, the RX 400h becomes the latest — and priciest — low-emission, fuel-saving hybrid on the market. The 2005 Honda Accord Hybrid, which starts at $30,505, has been the most-expensive hybrid until now. Other hybrids, including the Toyota Prius, Honda Insight and Ford Explorer Hybrid, are priced in the $20,000 to $29,000 range.

More horsepower than RX 330
The RX 400h looks much like the RX 330 — the mid-sized, five-passenger SUV on which it is based. With sales of more than 106,000 last year, the RX 330 outsells every other Lexus vehicle. But where the RX 330 is powered solely by a 230-horsepower, 3.3-liter, double overhead cam, gasoline V6, the RX 400h has a slightly less-powerful version of this V6 — with 208 horsepower — mated to two motive electric motors that, all together, provide 268 horses.

Toyota via Wieck The Lexus RX 400h engine compartment includes the silver Hybrid Synergy Drive system, which controls how the gasoline engine and electric motors interact.

One motor up front drives the front wheels; the rear motor powers the rear wheels when needed. The whole process is controlled by a computer as part of Toyota's patented Hybrid Synergy Drive system, which is now in its fourth generation.

Meantime, the RX 330 uses a six-speed automatic, while there is a continuously variable transmission in the RX 400h. The seamless mixing of the power sources as well as the torque is impressive.

On paper, the RX 400h has 212 foot-pounds of torque at 4,400 rpm. But the electric motors deliver the torque from 0 rpm, so the power comes readily and eagerly in the kinds of driving situations that most drivers face every day — accelerating from a stop, merging into traffic and passing other vehicles.

Test drive feedback
In the test drive of the RX 400h, for example, my driving companion got up over the speed limit smoothly, quickly and without realizing it while passing a vehicle on a country road. Indeed, the 0-to-60-mph time of 7.3 seconds reported by Lexus for this hybrid is equal to that of a Mercedes-Benz ML500 SUV with V8.

Toyota via Wieck The Lexus RX 400h interior includes a center console display that shows data like when the SUV is using just battery power, just gasoline, or both.

But the fuel economy is much better than a V8-powered SUV or even the regular gas-only RX 330. The federal government rating for the 400h hybrid is 31 miles a gallon in city driving and 27 mpg on the highway for a combined rating of 29 mpg. This is higher than the 27.8-mpg average rating for compact sedans and is 38 percent higher than the 21 mpg combined rating for an RX 330 with all-wheel drive.

In addition, the RX 400h puts out fewer pollutants, including 90 percent fewer smog-forming emissions than typical new vehicles. Some of the emissions improvement stems from the fact the RX 400h can drive short distances at slow speed on electric power only, leaving the V6 off.

The engine also can go off on its own at stoplights, where the driver may find himself suddenly enveloped in quiet. When a driver touches the accelerator again, the V6 may start up again to help supplement the electric power. Nothing's wrong. Its just the vehicle's way of being most efficient with its fuel, and it helps explain why the city fuel rating is higher than that for highway travel in this hybrid. On the highway, the gasoline engine has little opportunity to turn off, so more gas is burned.

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