How Hybrids Work

It's no secret that hybrid electric vehicles get pretty incredible fuel economy. In fact, the top three vehicles in EPA fuel economy ratings these days are hybrids, topped by the Honda Insight with its amazing 68 miles-per-gallon highway figure.


How do these vehicles accomplish such a seemingly impossible feat? Really, the answer is as simple as the current hybrid powerplants from Honda and Toyota are elegant.

Honda Civic Hybrid Engine
Historically, vehicles have been equipped with engines designed to handle all possible driving needs. While it may be that your daily driving might consist of heading to school or work, stopping by the market, and handling a variety of other errands, there's that occasional need to drive up a steep grade or get out of a tight spot with a quick burst of acceleration. To design a vehicle to do anything less is to sacrifice driver confidence and satisfaction, let alone safety.


That's why cars are equipped with engines much more powerful than needed most of the time. Though necessary, covering all possible needs is a dynamic that's also inefficient since, all things being equal, smaller engines are generally more fuel efficient than larger ones, sometimes significantly so.


Honda addressed this with the integrated motor assist (IMA) powerplant that debuted in its 2001 Insight hybrid electric vehicle. This two-seater uses a smaller-than-normal 1.0-liter, three-cylinder VTEC-E internal combustion engine that provides the power needed for most, but not all, everyday driving needs. On those occasions when heavy acceleration or climbing is needed, this hybrid turns to an ultra-thin, 10-kilowatt (13 horsepower) pancake-shaped electric motor located between the engine and transmission for supplemental boosts of power. Together, the two powerplants produce a combined 67 horsepower. Not a high-performance package, but one that confidently handles all driving needs.