The new RX 450h is rated at 32 mpg in the city and 28 mpg on the highway for a 30 mpg combined rating with front-wheel drive. Opting for all-wheel drive costs 2 mpg in city driving, but the highway number doesn't change (30/28).
The RX 450h’s hybrid system offers a 20% improvement in fuel efficiency over the outgoing RX 400h, which was rated at 27/24 mpg city/highway with front-wheel drive. In addition, Lexus says the hybrid system has better acceleration and cold-weather operability, plus reduced vibrations and noise. The RX 450h's 295-hp powertrain is more powerful than both the RX 400h's and the non-hybrid powertrain found in the RX 350.
Looking at the bigger picture, the RX 450h has the second-best fuel-economy rating of any SUV, after the Ford Escape Hybrid and its Mercury Mariner and Mazda Tribute hybrid siblings, which are smaller, less powerful SUVs. Even the fuel economy on the all-wheel-drive model beats all other crossovers.
The Lexus also bests its stable mate, the Toyota Highlander Hybrid. The Lexus RX 450h goes on sale later this spring. Pricing has not yet been announced.