The Toyota GR engine family is a gasoline, open-deck, piston V6 engine series. The GR series has a 60° die-cast aluminium block and aluminium DOHC cylinder heads. This engine series also features 4 valves per cylinder, forged steel connecting rods and crankshaft, one-piece cast camshafts, a timing chain, and a cast aluminium lower intake manifold. Some variants use multi-port fuel injection, some have D4 direct injection, and others have a combination of direct injection and multi-port fuel injection or D4-S.

Gasoline direct injection (GDI), also known as petrol direct injection (PDI), is a mixture formation system for internal combustion engines that run on gasoline (petrol), where fuel is injected into the combustion chamber. This is distinct from manifold injection systems, which inject fuel into the intake manifold.