In contrast to most production hybrids, which use a gasoline piston engine to provide additional acceleration and to recharge the battery storage, the Volvo ECC used a gas turbine engine to drive the generator for recharging. This type of engine has a higher thermodynamic efficiency than the conventional internal combustion engine with pistons.
In contrast to typical production hybrids that utilize a gasoline piston engine for enhanced acceleration and battery recharging, the Volvo ECC employed a gas turbine engine to drive the generator, which offers superior thermodynamic efficiency compared to conventional piston-based internal combustion engines.