Lexus RX 400h Hybrid

Lexus debuted the RX 400h at the North American International Auto Show in 2004, with plans to launch the vehicle in the U.S. market. The equivalent Harrier Hybrid debuted in Japan on 22 March 2005, the same day as the Toyota Highlander Hybrid. The Lexus RX 400h made its U.S. sales debut in mid-2005, with over 9,000 pre-orders at launch. The RX 400h's arrival in the U.S. had been delayed by several months; Lexus had announced in November 2004 that the American launch of the hybrid Lexus SUV would occur for the 2006 model year with European and Asian launches during 2005.

Since its launch, the all-wheel drive RX 400h Harrier Hybrid has been sold at a substantial premium over it's non-hybrid counterparts. In the U.S., the initial base price was US$49,185, which was a $5,600 premium over a similarly-equipped models. A front-wheel drive version of the Lexus RX 400h debuted in 2006, with a base MSRP approximately $1,400 less than the all-wheel drive RX hybrid. For 2007, along with the reduction of the federal hybrid tax credit for its hybrids, Lexus lowered the base price of the RX 400h to $42,580 and $41,180 for the respective all-wheel and front-wheel drive versions.

The gasoline-powered part of the RX 400h engine system is a 3.3 L 3MZ-FE V6, very similar to the one found in the RX 330. It produced, in the case of the Harrier Hybrid, 211 hp JIS (155 kW) and 288 N·m (212 ft·lbf). The gasoline engine is aided by a maximum of two additional electric motors, one driving the front wheels, producing 167 hp JIS (123 kW) and 333 N·m (245 ft·lbf) and connected to the CVT gearbox, and the other driving the rear wheels, producing 68 hp JIS (50 kW) and 130 N·m (95 ft·lbf). The whole system, called Lexus Hybrid Drive (also Hybrid Synergy Drive), produces a maximum of 272 hp JIS (200 kW). With Lexus Hybrid Drive, under normal driving conditions only the front motor and gasoline engine will be used. The rear motor will only be used under full-throttle acceleration or when the front wheels lose traction. The gasoline engine will switch off automatically and the car will be electrically driven when either stationary, decelerating, or being driven at a slow speed. A Ni-MH battery is responsible for powering the motors, and it is charged during deceleration.

The assistance of the electric motor increases the vehicle's performance; the Lexus 400h / Harrier Hybrid can reach 60 mph (97 km/h) in less than 8 s, quicker than the gasoline-only RX. Despite the increased performance, the Lexus RX 400h / Harrier Hybrid consumes roughly the same amount of gasoline as a compact four-cylinder sedan and it qualifies as a Super Ultra Low Emission Vehicle (SULEV) in America. Under the Japanese "10.15 mode" fuel consumption standard, the Harrier Hybrid can run 17.8 km per litre of fuel (compared with the standard coil-sprung V6 3.0 L Harrier, which returned 9.4 km/L). In Japan, it qualifies as a "4-star" LEV-car, where it produces 75% fewer emissions than the standard specified in Heisei 17 (i.e. year 2005). In the U.S., the Lexus  RX 400h is certified with a revised 2007 EPA fuel economy rating of 27 mpg city, 25 highway. Because of the manner in which the hybrid system operates, fuel economy is better in city driving, in contrast with conventional drive trains.

Compared to the standard Lexus RX, the RX 400h features a different front grille and round fog lights, and also differently-styled LED taillights in place of the conventional LED ones on the RX330/RX350. Different exterior colors are offered. When launched in 2005, the RX 400h came exclusively with brushed aluminum interior accents, in place of the wood trim offered in the standard RX. This changed in 2006, when the RX 400h became available with Bird's Eye Maple wood trim. Additional changes for 2006 included the addition of Hybrid badging on the rear side doors. A hybrid information display on the navigation screen shows electrical motor, gasoline engine, and regenerative braking activation in real time. Some Lexus RX 400h models without navigation screens display the information on a small monochrome display on the instrument panel, similar to Toyota Camry Hybrid models without navigation systems.

The Lexus RX 400h was one of only four SUVs to achieve recognition on J.D. Power and Associates' 2006 Automotive Environmental Index of the top 30 most environmentally-friendly vehicles. J.D. Power also awarded the RX 400h the top spot for entry-luxury SUVs in its 2005 Automotive Performance, Execution and Layout Study on owners' attitudes towards new vehicle designs. At the 2005 Green Fleet Awards in the United Kingdom, recognizing environmentally friendly transportation, Lexus was recognized for introducing the RX 400h with the 4x4 Manufacturer of the Year title. The RX 400h was named SUV of Texas at the 2005 Texas Truck Rodeo awards, and was awarded recognition as a CNET editor's choice vehicle in 2005.