The Lexus 400H is hybrid powertrain version of the popular RX330 SUV. Classified as a full hybrid, the RX is capable of running entirely on gasoline or electric power.The gasoline engine is a version of the standard 3.3L V6 found on the normal RX. Three electric motors are added for driving the front wheels, rear wheels, starting/stopping the gas-powered engine. All three motors act as generators for providing electricity back to the nickel model hydride battery pack. Electric steering and a continuously variable transmission are part of the hybrid package to keep operation of the powertrain seamless. All this complexity yields an RX that does 0-60 in a claimed 7.3 seconds which is a half second faster than the AWD RX330. Mileage is significantly improved from 18/24 MPG to an estimated 30/26.

The successful RX adds a gas/electric hybrid model for 2006 dubbed the RX400h. Classified as a full hybrid, the RX is capable of running entirely on gasoline or electric power. Electric steering and a continuously variable transmission are part of the hybrid package. Lexus claims a half-second improvement in 0-60 times and an increase in mileage to 30/26 from 18/24.