What do the rating stars mean?
From its launch in 2006, Lexus’ first hybrid proved that practicality doesn’t have to leave luxury in its wake. Combining the power of a 3.3-liter V-6 with electric drive motors, this AWD SUV provides the power of a V-8 with pleasing V-6 fuel economy. EPA estimates for the AWD are 26/24, the front-wheel drive are 27/24. With a base price of $42,580, our test model equipped with navigation rang in at $49,846. Warranty coverage on the hybrid battery and components is 8 years/100,000 miles and Lexus offers an owner support package with 24/365 roadside assistance and lodging.
Initial Impression: Elegant practicality
Christine: “Yeah, I was impressed. From far away or up-close, the RX 400h proved itself to be good-lookin’ and elegantly impressive. So this week I really wanted to see if Lexus’ motto, ‘in the pursuit of perfection’ would truly live up to itself. Would the price be worthy of me setting a goal to actually park one of these in our driveway in the future too?”
Scott: “I liked its aggressive stance—sort of a jacked-up, ready to go look. But when I climbed into the driver’s seat, it was smaller than I expected. Oh, it was comfy, stylish and elegant, no doubt—but I’m 6’4”, so it felt just a tad small.”
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Look & feel: Instant popularity
Get a Lexus and ya just might cruise into a new life. Sound too far-fetched to be true? Well, in our all too short period of our test drive week, we found friends and family to be “more than willing” to hop in and help accomplish our errands. Or just hop in for a quick ride. Were our personalities becoming more magnetic? Could this be the start of a charmed life? Time to nail down the reasons why.
Passengers were happy to be in the front or rear—and with 40/20/40-split rear seats with sliding and reclining adjustments, finding just the right position was almost all but guaranteed. And when it was time to load up the goods, no problem there either. Rear cargo capacity is 38 cubic-feet; seats folded equal 85 cubic feet. Add in the power-rear lift gate for non-fingernail breakin’ ease, and it’s a win-win for everyone.
While Christine found the 400h to fit her perfectly, Scott had a bit more trouble finding his comfort zone—plus visibility out the right rear proved to be edgy. Merging with traffic in NYC? Harrowing—especially when he wasn’t sure if that side mirror could give adequate coverage of that nebulous blind spot. While the back-up camera is a big helping hand, there’s little to see once darkness descends. Yet overall, with every day that passed, it became quite obvious that living with this Lexus would be quite easy. For now not only did we have a slew of friends ready at beck and call, we had a hybrid that got us where we were going with style and plenty o’ power. Leather seats ... navigation with energy consumption display ... premium audio system.
Fuel-ability: MPG not bad, but we want more
It was a workin’ week, with two trips to New York, we drove country, highway and city. Average mpg: 26.4. Not bad for V6 power—but then again---for a hybrid, was the extra technology of the hybrid components used to its fullest ability?
Was too much emphasis placed on the power in this SUV—leaving some fuel economy on the table? Our tester had the all-wheel drive option, and often, all-wheel drive systems tend to be a bit wasteful of fuel—however we really like the twist that Lexus took. Instead of using bulky drive shafts and transfer cases to transmit engine power to the rear wheels, they’ve incorporated an independent electric rear wheel traction motor. The beauty of this system: first, it’s completely automatic, governed by the onboard computer with no mechanical interfaces; second—and better still—it uses electrical power to provide traction to the rear wheels when road conditions warrant. This system is lightweight, engages and disengages instantly and requires no extra work—or extra fuel used by the engine. Bottom line: more fuel-efficient, all-wheel drive. Keep an eye on each mode on the hybrid monitor--from all-electric drive to battery charge mode, it's on display.
This notwithstanding, we wish that Lexus could have coaxed a little more fuel efficiency from this system. It’s really nice having that big V6 power when it’s needed, but could they have achieved the same result with a smaller engine—and tuning the hybrid system to take advantage of the big 123 kW front motor? We think so.
The Enviro-meter: The smooth Power-Split
Though we’ve knocked on the 400h’s fuel economy a bit and we like to see the electric portion of the hybrid system used to its fullest potential, we do acknowledge Lexus made major fuel mileage improvements over the standard RX 350. So, what what did they do—what’s the difference?
The RX 400h uses an advanced continuously variable transmission (CVT) with Power-Split. The Power-Split unit uses engine force to drive the wheels and the main electric motor separately. Under charging conditions this system allows the engine to drive the wheels and the main front motor/generator (MG) to charge the battery. During coasting the hybrid system shuts off the engine, then the rear MG joins the front MG to charge the battery. Additionally, the power steering pump, water pump and AC compressor are all driven by independent electric motors, rather than by the engine. All of these items reduce or eliminate load on the engine, helping the hybrid system to return its good fuel economy.
Fill the RX 400h’s 17.2-gallon tank at any standard gasoline station for a range of about 400 miles. With our mileage at 26.4, it was just a tad under the EPA 31/27 rating. Compare that to a 19 mpg average for a conventional RX 350 4WD, with a larger 19.2-gallon tank, yet a range of only 320 miles. According to fueleconomy.gov, greenhouse gas emissions for the hybrid tally up to 7.1 tons/year, whereas the regular RX 350 will spew out a higher 9.6 tons/year.