2008 Lexus RX 400h. Lexus introduced the world's first luxury hybrid SUV with the release of the RX 400h in 2006. A car-based, mid-size crossover, the gasoline-electric RX 400h shares much with its RX 350 sibling. However, in place of a 3.5-liter gasoline V6, the RX 400h uses a 3.3-liter V6 teamed with electric motors. The hybrid powertrain makes the RX400h fuel-efficient for an SUV, without compromising performance. 

Numerous midsize SUVs and crossovers, including the Acura MDX, BMW X3 and X5, Infiniti EX and FX and Mercedes-Benz ML350, are legitimate competitors for the Lexus RX 400h. But none of those vehicles offer a hybrid model, leaving the Lexus in a class by itself.