When it debuted in 1999, the Lexus RX300 led the vanguard of “crossover” vehicles: part car, part van and part SUV. So it only stands to reason that the highly acclaimed RX would serve as the launching pad for the first hybrid in its class as well, and essentially the only luxury hybrid on the market. And it will surprise few that the RX400h is every bit as accomplished as its sibling, in addition to serving up 33 percent better mileage (a combined 29 mpg). That boost comes from taking a variant on the RX330’s 3.3-liter V-6 and pairing it with three electric motor/generators. Precisely how these motors work together is something better left to Lexus engineers to explain; suffice it to say that the combination delivers 268 hp, compared with 230 hp in the nonhybrid. In essence, you are getting V-8 performance while maintaining mileage ratings double that of some SUVs. The only real noticeable difference in driving the 400h is at very low speeds, at which the gas engine isn’t operating. You’re left with the feeling of navigating a parking lot in some kind of space-age transporter that provides propulsion without the slightest sound.
Mercedes Benz E320 CDI
Are the guys at Daimler-Chrysler psychic, or just unwilling to turn their backs on good old German technology? Just when you thought the diesel engine was as dead as its 1894 inventor, Rudolf Diesel, along comes Daimler Chrysler with a new diesel-engined E-Class sedan, as well as plans to add a diesel to the Jeep Liberty. With gas prices bouncing around either side of $3 a gallon, the diesel is making a timely comeback. While the technology is not as daunting as the Lexus hybrid, its impact is equally noticeable. One listen to the CDI and you will understand that this is not your father’s diesel engine. A common-rail fuel-injection system shoots atomized fuel directly into the cylinders at extremely high pressure, virtually eliminating the clamorous sounds and noxious fumes of yore. The CDI engine delivers impressively on diesel’s promise of more torque, less fuel. Although the CDI is rated at a mere 201 hp (10 percent less than the gas engine), it delivers a whopping 369 lb. ft. of torque (vs. 232), peaking in a range of 1800 to 2600 rpm that is hardly above idle. This last fact is driven home in spades when you step on the accelerator and are instantly pasted to your seat before slowly easing as the tachometer approaches a low redline of 4600 rpm. Oh, we almost forgot: the EPA mileage estimate is roughly 40 percent better than the gas version (27 mpg city and 37 mpg highway).