Mileage Loop: Lexus RX 450h

The updated Lexus SUV hybrid, the Lexus RX 450h, is due out this Spring—with promised improvements in both performance and fuel economy compared with its predecessor. So we took out a test-loaner for a spin last week to see for ourselves.
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 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 like the instrumentation of the Lexus RX 450h: 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. The RX 450h has 27 extra horses coming from its new Atkinson-cycle V6. Total output is now 295 horsepower. 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.

Bottom Line: The RX 450h is an upscale crossover SUV that can easily achieve fuel economy in the low 30s—for a purchase price in the low- to mid-$40,000s.


  • CaptRon

    Staying within 10 mph of a mostly 40 mph speed limit tells me the speeds ranged from 30 to 50 mph. We could all improve our mileage no matter what type of vehicle, driving at those speeds. How about 70 to 80 on freeways combined with stop and go city traffic. I’m sure the RX-450h is a nice vehicle but I am skeptical of the mileage in a typical driving scenario. And at the price they will be asking…whew! Times are changing folks. Excess is no longer “in.” But only time will tell.

  • willypmd

    excess has always been and will always be “in”. From the romans to the french to today.

    I don’t care if the estimates are inflated 10-15%, I would much rather see someone spending the 40k on an SUV that gets 27 mpg to make them feel better about themselves than a freaking escalade that gets 12 mpg. Baby steps are better than no steps imo.

  • Ron Ivey

    Hahahaha! Well Willypmd, if you want people to buy a Lexus SUV to feel better about themselves, why do you care if someone buys an Escalade, a Lamborghini or even a Hummer to feel better about themselves? It’s their money, their choice, which is why I will probably put my 40k into a Chevy Volt or some other electric vehicle. I like the Volt’s technology with the onboard engine/generator since I drive only 20 miles a day, I would be able to get 200-300, or ad infinitum mpg. I love it. You’re right…excess has always been in but only for those who can afford it. For most of us…nahhhhh…it’s merely the road to an eventual bubble burst.

  • Lucien

    I assume the 40mph was on the 70% back roads and on the freeway the speeds were more like 60-70mph?

    Still great mileage for midsize SUV. I only wished Toyota would have made the design more exciting as well:-(. Time for other manufacturers to offer some competition.

  • Bobbi

    I really don’t understand getting an SUV if you’re trying to cut emissions … but I’m sure a hybrid SUV is better than a standard.