Hybrids combine a small combustion engine with an electric battery.
The two technologies can be combined to reduce fuel consumption and tailpipe emissions. A hybrid engine also operates more efficiently and produces less pollution than does combustion alone. With good design, hybrids can reduce smog pollution by 90 percent or more compared with the cleanest conventional vehicles on the road today. The Toyota Prius, for example, achieves a 90 percent reduction in smog-forming pollutants over the current national average. The cleanest hybrid will produce several times more pollution than a battery-electric vehicle.