Mitsubishi's smallest powerplants, most commonly found in their earliest models in the 1960s:
Where engine codes are used which include the supplemental letters, the first digit denoting the number of cylinders may be omitted, so 4G63T may be seen as G63T. 4G63T), 'B' that this is the second version of the engine (e.g. 'T' can indicate that the engine is turbocharged (e.g. There may also be supplementary letters after the initial four characters. It is not a guide to its place within that family, nor is it a guide to the capacity of the engine. The fourth (digit) is the specific engine model within the family.Five of the '4Gxx' straight-4 engine families had distinct names '4G1' = Orion, '4G3' = Saturn, '4G4' = Neptune, '4G5' = Astron, and '4G6' = Sirius. The third (digit) previously denoted the engine family.
Their latest engines, however, do not follow any previous conventions (e.g. Two engine families were introduced using the letter 'A' to denote that all the engines in the family had an alloy cylinder head. However, since the 1980s, this has changed. Mitsubishi engines designed since 1970 use a four-digit naming convention:
