Issues in focus
| Vehicle type | Description |
|---|---|
| Micro hybrid | Vehicles with gasoline engines, larger batteries, and electrically powered auxiliary systems that allow the engine to be turned off when the vehicle is coasting or idling and then quickly restarted. Regenerative braking recharges the batteries but does not provide power to the wheels for traction. |
| Hybrid electric (gasoline or diesel) | Vehicles that combine internal combustion and electric propulsion engines but have limited all-electric range and batteries that cannot be recharged with grid power. |
| Diesel | Vehicles that use diesel fuel in a compression-ignition internal combustion engine. |
| Plug-in hybrid electric | Vehicles that use battery power for driving some distance, until a minimum level of battery power is reached, at which point they operate on a mixture of battery and internal combustion power. Plug-in hybrids also can be engineered to run in a "blended mode," where an onboard computer determines the most efficient use of battery and internal combustion power. The batteries can be recharged from the grid by plugging a power cord into an electrical outlet. |
| Electric | Vehicles that operate by electric propulsion from batteries that are recharged exclusively by electricity from the grid or through regenerative braking. |
| Flex-fuel | Vehicles that can run on gasoline or any gasoline-ethanol blend up to 85 percent ethanol. |