Hybrid vehicles combine an electric motor with an internal combustion engine. The hybrid's key distinct advantages are the utilization of the established fueling infrastructure, reduced emissions and extremely high fuel economy - up to 66 highway mpg. Some hybrids drive exclusively using electric power during slower speeds, an internal combustion engine at higher speeds, and both power plants under certain driving conditions. Others use an extremely efficient internal combustion engine at all times with electric motor boost as needed. In both configurations the internal combustion engine extends the driving range, eliminating a critical limitation with pure battery electric vehicles.

Currently there are significant numbers of gasoline-electric hybrid vehicles on the road. Some hybrids use smaller-than-normal, highly efficient three- or four-cylinder internal combustion engines, combining with electric motors to add the levels of power required for a satisfying driving experience. Larger V-6 and V-8 hybrids are an interesting deviation from this scenario as these hybrid options provide higher levels of performance than their internal combustion variants.

Another hybrid variant is the "mild" parallel hybrid. Mild hybrids use a simpler system that employs engine stop and start, resulting in more modest fuel economy gains in the 10-15% range.