The Mitsubishi Astron or 4G5 engine, is a series of straight-four internal combustion engines first built by Mitsubishi Motors in 1972. Engine displacement ranged from 1.8 to 2.6 litres, making it one of the largest four-cylinder engines of its time. It became the first Japanese production engine to combine both electronic fuel injection (EFI) and turbocharging. It employed a hemispherical cylinder head, chain-driven single overhead camshaft (SOHC) and eight valves (two per cylinder). United St...