The first-and, so far, the only-hybrid-powered luxury SUV, the RX400h is propelled by a 3.3-liter V-6 teamed with two electric motors, one for the front wheels and one for the rear. The three-part powertrain produces a combined 268 hp while returning 31 mpg in city driving and 27 mpg on the highway. This green machine also whooshes from 0 to 60 mph in just over seven seconds.