Gasoline- or diesel-powered engines excel at sustaining high speeds but have a harder time overcoming inertia to get moving.
Hybrid electric vehicles are more fuel efficient than internal-combustion engine (ICE) cars because they use stop-start technology, which reduces idle time, and regenerative braking, which recovers the energy that would otherwise be dissipated when brakes are applied. They are distinct from electric vehicles, which are powered, in part or in whole, by grid electricity.
Hybrid electric vehicles supplement an internal combustion engine with at least one electric motor and a battery large enough to power the vehicle by generated electricity.