From 1999 to 2006, the Insight relied on Honda's Integrated Motor Assist (IMA) system. The IMA system helped the electric motor to run start and stop sequences with the gas engine during certain driving conditions. This system also kept the hybrid battery charged by turning the engine into a generator.
Thanks to this hybrid-wizardry, the Insight gets fuel averages of 40 mpg in the city and 43 on the highway according to the EPA. While these ratings are fantastic when compared to gasoline cars, other hybrids do better. The Toyota Prius gets an EPA rating of 51/48 mpg city/highway, making it the most fuel efficient car available in the United States. The Prius starts around $23K, which is a few thousand more than the Insight, but if you plan on keeping your car for a few years, the Prius will save you more money in the long run. The Honda Civic Hybrid also has higher ratings -- 40/45 mpg city/highway -- but will also cost you just as much as the Prius and doesn’t perform as well as the aforementioned competition.
The Honda Insight is powered by an Integrated Motor Assist (IMA) system