The Lexus RX 400h is a model of automobile assembled by Toyota Motor Corp under the Lexus brand name. After first being introduced in January 2004 at the North American International Auto Show, it would become the world's first mass-produced hybrid SUV. Indeed, it features a "full hybrid," rather than partial hybrid, system (CanadianDriver, 2004).

The petrol-powered part of the engine system is a 3.3 L V6 (the same one found in the RX 330). Because of the help of the electric engine, however, it can reach a speed of sixty mph in less than eight seconds—quicker than the petrol-only RX 330. (Because of a rear-drive electric motor, an optional all-wheel drive system can increase the rate of acceleration.) Despite this, the RX 400h consumes roughly the same amount of petrol as a compact four-cylinder sedan; it qualifies as a Super Ultra Low Emission Vehicle (SULEV) (CanadianDriver, 2004).

References