Hybrid Gets 150 Miles Per Gallon Using Ultracapacitors

It’s a prototype hybrid car that gets 150MPG, and goes 40 miles on electricity alone, drawing its power from a combination of lithium-ion batteries and ultracapacitors. The ultracapacitors provide a burst of energy to the engine, when needed. They are then recharged by the lithium-ion batteries. This avoids the problem of emptying the batteries too fast, which can cause them to heat up, and possibly catch on fire.