Lexus RX450h tested: The hybrid you control with a mouse

By Rory Reid on 12 May 2009, 5:08pm

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Lexus RX450h tested: The hybrid you control with a mouse Image 1

The Lexus RX450h makes absolutely no sense. It's the size and shape of a small barn, yet it's more fuel-efficient than a Ford Mondeo. It's a so-called Chelsea Tractor, yet it can be as kind to the environment as an all-electric G-Wiz. It's a road car, yet it mixes technology from fighter jets. Oh, and you control it using a mouse. WTF?

Eeek! A new user interface!

First things first -- that mouse thing, or Lexus Remote Touch, as its designers call it. Sat down by the centre console between the front seats is a knob that controls the movements of a cursor on an 8-inch multi-display screen mounted in the dashboard. The knob operates on the same basic principles as a mouse and even vibrates as you hover over each menu item to make them easier to select. It's ridiculously easy to use while the vehicle is stationary, but we're reserving judgement until we see if the bodycount goes up once the general public start using it while the car is in motion.

Heading on up

Next, the fighter jet technology. The RX450h packs a head-up display system that projects key driving data into the driver's line of sight at the base of the windscreen. Speed, navigation commands, audio information and more are visible in your direct line of sight, so there's almost no reason to take your eyes off the road. This particular implementation was thoroughly impressive -- we had no trouble reading the display, even in bright sunlight, and it never once looked blurry.

A sound investment

If you're buying a luxury car, you're damn sure going to need a luxury sound system. The standard audio package in the RX450h is fine for grannies and school-run mums, but the premium Mark Levinson upgrade is where it's at. This system produces 5.1-channel surround sound through 15 separate speakers, including four 25mm tweeters, five midrange speakers -- including one mounted centrally on the dashboard -- and a 200mm subwoofer. It's loud, well balanced and never once sounded as if it was struggling -- even at maximum volume. It'll play audio from a built-in 40GB hard drive, audio CDs, video and audio DVDs, USB hard disks as well as iPods -- so take your pick.

How many engines?!

Fitting a hybrid propulsion system into a car the size and shape of a small barn sounds pretty illogical to us, but try telling that to Lexus' engineers. They've shoehorned not one, not two, but three separate motors under the RX450h's skin. The primary motor is a 3.5-litre V6 packing 246bhp. The remaining two are of the electric variety. One unit, mounted at the front, produces 174bhp, while the rear-mounted motor produces 156bhp. Together, they help the RX450h hit a maximum speed of 124mph and 0-60mph takes just 7.9 seconds -- not bad for a car that weighs almost as much as three Ford Kas.

The RX450h is the first SUV we've encountered -- crossover or otherwise -- to have an electric-only driving mode. Simply cycle through the various driving modes using a button on the steering wheel (Eco and Snow are also available) and you've got yourself a 3-tonne G-Wiz. It's not all sunshine and lollipops, though -- the vehicle's range in this mode is less than 3 miles, and it's only available when there's a sufficient charge in the battery, which is surprisingly infrequently if your right foot is a little on the heavy side.

Overall fuel economy, however, is impressive. The RX450h has a combined cycle figure of 44.8mpg, CO2 emissions of just 148g/km, and will cost you just £125 in road tax. For reference, a Ford Mondeo (2-litre TDCi 140ps) spits out 187g/km, gets 39.9mpg and will cost you £215 in tax.

Will it bend?

Despite its wealth of technology, the thing that stood out most about the RX450h was the slightly disappointing driving dynamics -- it's just not very good at going around corners, and that's quite important unless you live in America. Its designers have gone to great pains to include a suspension system that automatically firms itself up for bends, and relaxes again for straight roads, and there's even a version of the RX450h with air suspension, but neither gives you a great deal of confidence when negotiating bends. Still, school run mums, eco-aware rappers and city workers probably won't mind as long as they've got that lovely 'L' on the grille.

The RX450h is available to buy now from £41,600, while the top of the range premium model with all the goodies retails for £55,505. Watch for a full Car Tech test-drive video shortly, and in the meantime click through for more photos.