Hybrid power trains
Although it didn't make the top 5, we give gas-electric hybrid power trains an honorable mention here because they offer the best of both worlds: more power and better fuel economy. Just compare the Lexus RX 450h
with the Lexus RX 350
. The hybrid system achieves this seeming miracle by collecting energy from braking and excess engine power that would otherwise be wasted, and making it available to drive the car's wheels.