The 1.8L 20V turbo engine in the Golf GTI Mk4 has 5 valves per cylinder. Its “20V” designation means five valves in each of four cylinders, for 20 valves total.
The engine is part of Volkswagen Group’s well-known 1.8T family, a turbocharged, intercooled inline-four petrol engine used across Volkswagen, Audi, SEAT, and Škoda models. In the Mk4 GTI, it helped give the car a strong blend of everyday drivability and tuning potential.
The unusual five-valve layout uses three intake valves and two exhaust valves per cylinder. Compared with a conventional four-valve arrangement, the extra intake valve can improve airflow and help the engine breathe efficiently at higher engine speeds.
A frequent mistake is reading “20V” as a trim name or assuming it means 20 valves per cylinder. It means 20 valves across the complete four-cylinder engine. The later Golf GTI generations moved to different engines and valve layouts, so the figure belongs specifically to this Mk4-era 1.8T configuration.