 On the contrary, in most HEV designs, the ICE operates closer to its range of highest efficiency more frequently.The power curve of electric motors is better suited to variable speeds and can provide substantially greater torque at low speeds compared with internal-combustion engines.The greater fuel economy of HEVs has implication for reduced petroleum consumption and vehicle air pollution emissions worldwide

Many hybrids use the Atkinson cycle, which gives greater efficiency, but less power for the size of engine.