Reviews March 30, 2010, 3:58PM EST

Review: 2010 Lexus RX 450h

The new Lexus RX 450h luxury hybrid SUV offers both better mileage and power than the conventional RX 350 for only $5,000 more

By Thane Peterson

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Editor's Rating:

The Good: More space, only $5,000 more than non-hybrid model, 30 mpg!

The Bad: Reliability doubts raised by Toyota's many recalls, small design glitches

The Bottom Line: It's no Prius, but it helps take the guilt out of luxury SUV ownership

Reader Reviews

Up Front

In my opinion, we can take either of two basic approaches to improving the fuel economy of North American vehicles. The first is that we all go out and buy a 2010 Toyota (TM) Prius, far and away the most fuel-stingy and environmentally friendly production vehicle on the market. The second is to improve the mileage of every type of vehicle. If consumers insist that they need, say, an SUV, a big luxury sedan, or a full-size pickup truck, respect their wishes, but make sure those vehicles become far more efficient than they have been in the past.

Approach No. 2—which, obviously, is more practical than Approach No. 1—leads us to consider the new Lexus RX 450h, the hybrid-powered version of Toyota's popular Lexus RX 350 midsize luxury SUV. The new RX 450h is better than the RX 400h, the model it replaced, with more space, more power, and better fuel efficiency. Most people can buy one instead of a conventional gasoline-powered RX 350 without giving up anything—whether it be money, convenience, or performance. Also, as of this writing, no recalls have been announced on the RX 450h, so the model hasn't shown any of the braking glitches that have plagued the 2010 Prius.

With front-wheel drive, the RX 450h gets 32 mpg in the city and 28 on the highway, for an average of 30; with all-wheel drive, the numbers fall to 30/28 and an average of 29. That's excellent for an SUV—9 mpg better, on average, than a comparable 2010 RX 350. But it's still way behind the Prius' average of 50 mpg.

The RX 450h starts at $43,560 with front-wheel drive and $45,150 with all-wheel drive, about $5,000 more than a comparable gasoline-powered RX 350. However, the average American buyer keeps a new vehicle for about six years, according to the Power Information Network (PIN). With premium gasoline at around $3.00 per gallon, and likely to rise at least a little in coming years, most owners will recover most or all of the price premium in fuel-cost savings (more details later). The hybrid's CO₂ emissions are significantly lower than the conventional model's, so you'll be going easier on the environment, too.

The RX 450h has a more powerful engine than its conventional cousin, with a 3.5-liter V6 gasoline engine and two (three with all-wheel drive) electric motors that generate a combined 295 horsepower, 20 more than the RX 350's V6. The only transmission offered in the hybrid is a continuously variable automatic, vs. a six-speed automatic in the RX 350.

The RX 450h doesn't yet have government crash-test ratings. However, it is probably about as safe as the RX 350, which has five-star ratings in every category except rollovers, where it earned four stars. The RX 450h comes standard with a full range of airbags, as well as stability and traction control and braking assist.

Lexus expects to sell about 18,000 RX 450h's annually, though sales are off to a slow start this year. Only 1,906 were sold in the first two months of the year, down from 3,058 RX 400h's sold during the same period in 2009. Lexus sold about five times as many RX 350s as RX 450h's in the first two months of this year.

Behind the Wheel

The Lexus RX 350 I recently test-drove had a number of annoying creaks and rattles in its cabin, and I couldn't get the rear hatch cover to stop rattling; even though the RX 450h's interior is almost identical, it had none of these problems.

I don't know why the hybrid feels better-built than the RX 350. Perhaps it's because my RX 350 had more miles on it (around 13,000 miles vs. around 8,000 for the RX 450h). Or perhaps it's because the RX 450h is built in Japan and the RX 350 I test-drove was built in Ontario. However, I had the same reaction when I test-drove the 2007 RX 400h: It seemed more tightly built than a Lexus RX 330.