Lexus RX 450h

By Brad Berman and Larry E. Hall

By most standards, Lexus’s luxury SUV hybrid has been a smash success since its introduction in 2005. A significant number of Lexus SUV buyers opted for the “hybrid upgrade,” making the Lexus RX 400h, as it was previously known, almost as popular as the Ford Escape Hybrid and the Toyota Highlander Hybrid. Still, reviewers at the time questioned the desirability of a vehicle that costs between $5,000 and $20,000 more than its competition but nets a fuel economy boost of only 5 mpg from its hybrid system.

After leaving the original RX hybrid series dormant in 2009, Toyota came back in the 2010 model year with the 450h, which offers more power and significantly improved fuel economy. In other words, they upped the ante—and it worked. The Lexus RX 450h was the most popular hybrid SUV for most of 2009, and all of 2010.

What’s the significance of the shift in the vehicle’s name-number from 400h to 450h? In the gas-powered versions, the number is a code for the engine displacement—so the RX 350 means the vehicle carries a 3.5-liter engine. Lexus nudges those numbers up on the hybrids, because RX 450h’s combination of a 3.5-liter V6 engine and rear-mounted electric motor-generator gives it the performance of a 4.5-liter engine.

For the 2011 model year the RX 450h has minimal changes. A 12-volt outlet inside the center console was relocated outside for more convenient access, and the compass on the inside rearview mirror is deleted when ordering the optional navigation system because the new system has a built-in compass. Lexus also eliminated the Sport Package.

The RX 450h is available in a two-wheel drive model starting at $43,935, and an all-wheel drive version priced at $45,525. Most all-wheel drive vehicles compromise efficiency due to extra weight from mechanical components. Lexus addresses this issue by providing regenerative capabilities to all four wheels. The result is a more efficient process of recapturing energy.

More Power and More MPG

The 2011 RX 450h boasts the latest incarnation of Toyota’s Hybrid Synergy Drive, which works in tandem with a new and improved gas engine. Two new fuel-saving strategies have been implemented in the hybrid system. One is an exhaust-heat recovery system that reduces the time it takes for the engine to warm up. This allows the idle-stop feature—which shuts down a hybrid’s engine and allows the electric motor to take over—to engage more frequently and for longer durations, improving fuel economy and reducing emissions. The other innovation is a cooled exhaust-gas recirculation system. This feature boosts fuel economy by reducing engine pumping losses.

Combined, this larger powerplant produces 295 horsepower—27 horses more than did the RX 400h. But despite the added power and the fact that the vehicle is slightly larger than its predecessor, the 450h actually nets 5 mpg more in fuel economy, making it the most fuel-efficient all-wheel drive SUV on the North American market.

This is one of the few luxury hybrids on the market whose fuel savings will actually pay for the so-called “hybrid premium” over the average life of the car. The 450h’s starting price of just under $44,000 means that the added fuel economy comes at a cost of around $5,500 over its non-hybrid sibling, the RX 350. For city driving, this efficiency boost is 14 mpg, on the highway the difference is a much more modest 3 mpg.

Reviewers praise the seamlessness of the SUV’s hybrid powertrain and the smoothness of its ride, but some found it a bit dull. “The RX rides smoothly and is very quiet but is not a heck of a lot of fun to drive,” said Bloomberg. “In truth, it’s a minivan in disguise.” For a car whose sticker price is north of $40,000 that’s a low blow, particularly since the RX 450h only seats five.

But the “fun factor” isn’t the whole story when it comes to the RX 450h. Sure it’s what gets people who test drive cars for a living out of bed every morning, but most drivers are looking for something smooth, safe and fuel efficient—qualities the RX 450h has in spades. Autoblog puts it in better perspective: “There are certainly more entertaining, attractive and powerful ways to transport five people and their weekend getaway gear, but that’s never been what the RX is about. Simply put, it’s about the destination, not the drive.”

Exterior

The 450h has picked up an extra inch of length and a few inches of width; a difference that USA Today says makes “a big difference to the eye. The new one looks sleeker, less lumpy.” The new 450h is based on a completely redesigned RX line, which boasts sharper styling that builds upon a Lexus aesthetic that is becoming increasingly iconic.

Critics blasted early Lexus models for failing to distinguish themselves from the competition—some said the cars looked as if they had been pasted together from the scraps of other luxury autos. That is no longer the case. Lexus now employs an aesthetic philosophy it calls “L-Finesse,” which, if nothing else, has helped it forge a distinct stylistic identity as a carmaker. The RX 450h embodies the second generation of L-Finesse styling with its fastback profile, low-set grill and sharp angular elements.

The RX 450h hybrid has a few styling features that are distinct from the RX 350, including a stylized grille and front bumper, hybrid badging with blue-trimmed Lexus logos, a 19-inch optional wheel design, and blue-tinted headlamps and tail lamps.

Interior

Inside, the RX 450h is everything you’d expect from a luxury SUV, but some features you might expect to come standard will cost you a little extra. The 450h comes standard with 10 airbags, a nine-speaker sound system, an interactive information screen, dual-zone climate control among others, but if you really want the full luxury car experience you’ll have to pay more. Twelve and 15-speaker sound systems are available, as are video monitors for blind spots, and most importantly, Lexus’ new Remote Touch control system.

Lexus thinks Remote Touch will be the technology that replaces touch-screen consoles, which require too much attention and reach from the driver. With Remote Touch, the driver can navigate the vehicle’s onboard computer using a small touch-activated joystick located at the base of the center console. Though there is a bit of a learning curve, once you get the hang of it remote touch is a revelation, and one of the reasons CNET called the 450h “one of the more technically advanced cars available today.”

Critics were unanimous in their love for the RX 450h’s wooden steering wheel and optional leather seating, which the New York Times says is “the creamiest leather this side of a Bentley.”

Real World MPG Test Drive

A few weeks before the RX 450h’s arrival in the spring of 2009, we took out a test-loaner for a spin to see for ourselves if the new hybrid delivered the promised improvements in both performance and fuel economy. Our route was a 127-mile course from Aberdeen, Maryland to York, Pennsylvania and back down to Frederick, Maryland. The travel was comprised of approximately 30 percent highway driving and 70 percent back roads and country routes. The conditions were pretty ideal—mostly 40 mph two-lane routes winding through a few small towns with the occasional traffic light.

The Lexus RX 450’s mileage over the course of our 127-mile route was 31.6 mpg, easily beating EPA numbers.

The Lexus 450h claims government fuel economy of 28 city/27 highway—a healthy jump over the previous model, the RX 400h, which carried a rating of 27 city/24 highway. We applied a moderate driving style, staying within about 10 mph of the speed limit. We did punch it here and there to test acceleration, but nothing crazy.

The results? We easily beat the EPA numbers, achieving 31.6 miles per gallon. The 15 percent improvement in the new model is due to a number of modifications in the Lexus Hybrid Drive system:

• Lighter electric motors
• Smaller, lighter battery
• Smaller, lighter Power Control Unit (40 percent smaller)
• Exhaust Gas Recirculation System (eliminates the need to enrich fuel by lowering exhaust temperature)
• Exhaust Heat Recovery System (speeds engine warm-up by circulating coolant)

We particularly liked the instrumentation of the new RX: To monitor efficiency, the 450h comes equipped with a very simple gauge. The needle indicates how the hybrid system is responding to your driving, by dropping into one of three modes: charge-mode, usually during braking or slowing; eco-mode, accompanied by an eco-light; or power-mode, during harder acceleration. These classifications are becoming common in all Toyota hybrids. There is a separate digital readout which provides the instantaneous miles-per-gallon. An arrow points out how the hybrid system is operating—electric, engine, or both together. It’s all very straightforward. No fancy animation of leaves or trees—just smart, right-to-the-point, and very useful.

Along with excellent mileage, the 450h granted a noticeable improvement in power. Merging, passing, and moving through fast traffic were effortless.

In terms of handling, the 450h is also very much on point. Our all-wheel-drive tester—with its third electric motor for the rear axle—helped on this front. Like its gas-powered counterpart, the 450h has a very sporting and car-like feel. It takes corners confidently, with very little body roll. On the highway, you get a soft, quiet, and comfortable ride.

The RX 450h is packaged very similarly to the 400h—which is to say, roominess and configuration are virtually the same. The RX 450h is styled for a slightly more aggressive and sculpted look, with bolder lines.

One qualm that you might have with the RX line is that it doesn’t offer optional third-row seating. It's certainly large enough and since it’s based on the Toyota Highlander, you might expect to be able to seat more than five. Still, with a generous cargo area of 40 cubic feet and plenty of comfort for backseat passengers, it’s hard to complain—particularly if you bare in mind that it’s a luxury SUV that gets better fuel economy than most luxury cars.

Prices are Manufacturer Suggested Retail Price (MSRP) at time of publication and do not include destination charges, taxes or licensing.

This article was updated on Mar. 3, 2011. The comments in the thread below started when the article was first published.

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