2006 Lexus RX400h

A cursory glance at Lexus’s latest hybrid reveals little out of the ordinary. Indeed, rather than shouting its green status to the world the RX400h says it in very subtle ways.

A closer look reveals a grille in the middle of the bumper fascia (to feed the hybrid its much-needed cooling air), but that’s about it externally. Inside, the same discrete approach is found. The utility demanded of an SUV is in place, including fold-down rear seats, and the luxury for which Lexus is noted for is all present and correct. Only an overly busy screen at the top of the center stack gives away the game. This thing shows what the hybrid system is up to – driving the RX with its electric motor, the gas engine or both and when the system is recharging its main battery. Naturally, it also includes a read out for overall fuel economy. As I say, overly busy.

Beneath the shiny sheet metal, however, the RX400h is different to every other SUV out there (the Ford Escape being the exception), as it serves to demonstrate not only how far the modern hybrid has come in a few short years, but what the potential is when it is used creatively.
The original Toyota Prius sauntered its way to 100 km/h in 14.5 seconds, which hardly set the world abuzz. After some serious development work, the 0-100-km/h time dropped to around 12 seconds, which put it within hailing distance of class standards. When, in 2004, the latest Prius arrived it finally did cause quite a stir, as it had blossomed into a realistically sized hatchback with real-world power and acceleration (10 seconds to 100 km/h), as well as even better fuel economy. The Prius’s hybrid powertain had finally come of age.

Taking this technology and applying it to an SUV makes a world of sense and is the next logical step as many sport-ute fans typically don’t worry about fuel economy until after buying the truck and they have started to pay for the gas – the biggest single complaint with the Hummer in its first 90-days of ownership is its thirst for fuel, duh!

True, the RX400h hybrid does trade off a little of the Prius’s fuel efficient focus in favour of significantly better performance, but it does not forget its roots.
At the heart of RX 400h’s drivetrain is the latest iteration of Toyota’s Hybrid Synergy Drive system. As before there is a large battery (288-volts), a ton of electronics and a gasoline/electric hybrid up front. In this case, it’s a 3.3L V6 (good for 208 horsepower and 212 pound-feet of torque) and an electric motor that twists out 165 hp and 262 lb-ft of torque anywhere between 0 and 1,500 rpm. This combination brings both brisk performance and remarkable fuel economy.
Adding a second, optional, electric motor (that drives the rear wheels) transforms the RX400h into real ripper while adding a true on-demand, all-wheel-drive capability. While the second electric motor is only rated at 67 hp and 96 lb-ft of torque (between 0-610 rpm) firing it to the wheels through a reducer brings the equivalent of 650 lb-ft of torque and a realistic peak horsepower of 270 – some miscreants add the engine’s peak output to the electric motor’s peak output, which is totally misleading and an inflated view of the real numbers.

To demonstrate just how well it all works, Lexus turned a bunch of we journos loose on a drag stripe. Matting the RX’s gas elicited a loud chirp (from all four tires!) and a run that saw the RX rip through 100 km/h in less than 8 seconds. More impressive, however, is that a little over two-thirds of the way down the drag strip the speedo flashed through a 160 km/h in under 15 seconds, which is nothing short of remarkable.

In the meantime, that gaudy central readout on the dash was displaying an average fuel economy of 8.9 L/100km. The bottom line is a simple one – the RX400h performs exactly as advertised: Four-cylinder fuel economy, V8 torque and truly raucous performance. It is a blend of environmental responsibility and performance that was not, until now, even on the radar.

The RX400h also uses some nifty technology to further the performance/economy cause. Along with regenerative braking (here the electric motors reverse function to recharge the main battery, so the RX never needs to be plugged in) the power steering and air conditioning are electrically driven. This allows the systems to work even after the engine has shut down at a stoplight – another of its fuel saving ploys.
Even the all-wheel-drive system chips in. Not having to drive a transfer case and rear axle cuts down on the fuel this normally consumes. Better yet, as the electric motor is always ready to go, it delivers is a pro-active AWD system that anticipates a loss of traction and addresses it almost before it becomes an issue. It even uses the latest dynamic stability control system to keep the driver on the straight and narrow – as with the AWD, it recognizes and corrects a problem before it becomes an issue, which makes it much less intrusive.

As a package the RX400h is complete, as it delivers all the required luxury and utility without compromise. It is also a remarkably simple automobile that, in spite its overall complexity, delivers on three important fronts simultaneously. First, it brings the fuel economy and ultra low emissions of a four-cylinder engine and the torque and performance of a big V8. Second, all of the learning that went on in the development of regenerative braking, improving efficiency and the real-world use of high-power electronics and electric motors is paving the way for the day when a fuel-cell vehicle becomes a reality. Third, and perhaps most importantly, it rides and drives like any other automobile, which is the biggest complement of all.