Wheels – Lexus RX 400h

Clearing the Air — The eco-friendly Lexus RX 400h offers a practical alternative to gas-guzzling SUVs.

Pat Devereux Shopping

If you didn’t already know, you could be excused for thinking the “h” in Lexus RX 400h stands for “hot.” One of the most anticipated launches in recent memory, the 400h timed its run into the market perfectly. Just as gas prices were looking like they would only ever increase and SUV values headed toward zero, along came the Lexus 400h, an economical and low-polluting SUV.

Its secret is that the “h” stands for “hybrid.” And it is the first SUV to feature a gasoline/electric drive train, which claims to offer the gas mileage of a V6 with the power of a V8 and the emissions of a toy. The really clever part is that Toyota has trained everyone with its Prius that hybrids are quite cool. So when Lexus announced the 400h, salespeople had to write orders with both hands to keep up. It became the most pre-ordered vehicle in the brand’s history.

Without going into the argument for and against hybrids, after all this hype it would be fair to expect a good deal more car and significantly less gas usage and emissions than the standard RX 330, on which the 400h is based. The 400h currently commands a price premium of about 25 percent more than the 330, and that’s before the dealer adds any queue-jumping fee. So what, exactly, do you get for that sizable extra sum?

On first sight, a reshaped front fender, a new grille, LED taillight clusters, and a set of 18-inch aluminum wheels. The eagle-eyed will also notice aerodynamic underpinnings that help keep the car as streamlined as possible and fuel consumption down.

At its heart is the same 3.3-liter V6 that powers the best-selling RX 330. But the difference is that in the 400h it is supplemented by three electric motors. The first acts solely on the front wheels, the second solely on the rear. The third functions as a starter motor and generator. So there’s a lot of extra mechanical baggage — 300 pounds worth, to be precise — to be carried around.

This boosts the performance in pretty much every dimension. Compared with the 330, power is up by 38 horsepower, it’s a half-second quicker 0 to 60 mph, and it claims to get up to 31 mpg around town — a significant leap from the 18 mpg city mileage claimed for the 330.

However, gas mileage depends so much on driving style, hybrid or not, that it’s hard to see these figures as any more than a rough guide. Look on any of the online chat sites about hybrids and you’ll find people who get more than that — and a lot who get substantially less.

Clear as day are the 400h’s credentials as a Super Ultra Low Emission Vehicle, which places it in the virtuous section of the automobile world.

But then there are questions to be asked there, too. For example, what happens to all those batteries sitting under the back seat when they reach the end of their natural life? Lexus is working on a plan for this, particularly as its parent Toyota is planning on introducing many more hybrid models. But for now uncertainty prevails.

Driving the 400h presents far fewer questions. Inside the cabin, three gauges tell you what the drive train is up to — running on electric, gas, gas/electric, nothing, or recharging itself.

Drivers can also hear all of the engine’s exertions. Despite the fitment of a sound-deadening windshield, quieter cooling fan and electric power steering and air conditioning, when you accelerate hard, the drive train makes its presence known to all in the car in a most un-Lexus-like way. The variable transmission, which is a simple pleasure to use, is the main culprit here. It wouldn’t stop you from wanting to drive it, but the engineers should go back and hush the noise issue.

That said, the vehicle offers significantly more pickup from the get-go — thanks to electric motors producing their max torque from their first revolution — and when overtaking, when all the engines work together to push the 400h along. Otherwise, the 400h is much like its 330 cousin to drive — remarkably easy, handling like a regular sedan, with plenty of room for people and their stuff.

And it comes with the unbeatable Lexus service and warranty.

One thing that might invalidate the latter of those, and which may come as a surprise to anyone expecting an SUV to be an all-roads type of vehicle, is that the 400h can not be used off the roads. Doing so threatens the cooling of the rear electric motor and so is frowned upon by Lexus. While we all know that most SUVs are rarely challenged by more than a deep puddle, this seems a backward step for such a forward-looking vehicle.

But then maybe it’s being realistic. Why build in functionality that no one ever uses? Better to spend the time, energy, and cash creating a vehicle filled with features that people want in a design they know and like. Features that save them time and money — and the planet, too.