The Mitsubishi 4G9 engine is a series of straight-4 automobile engines produced by Mitsubishi Motors. All are 16-valve, and use both single- and double- overhead camshaft heads. Some feature MIVEC variable valve timing, and it was the first modern gasoline direct injection engine upon its introduction in August 1996.
4G91
The 4G91 uses a bore and stroke of for a total displacement of . With a 9.5:1 compression ratio and DOHC, four-valve-per-cylinder head and multi-point EFI, this engine produces at 6,000 rpm and at 5,000 rpm. The 4G91 was a short-lived model, mainly built between 1991 and 1995 and rarely seen in export markets. There was also a carbureted model, with at 6,000 rpm and at 3,500 rpm.