I am trying to figure out what the letters and the numbers in the Engine Codes for the Mitsu's are... I saw it somewhere but I cannot remember what they meant.. I know the first number in the series means the number of cylinders
E.g 4G63, 6G72, 6A12.. etc... but what to the rest mean?.. and it's strange that I cannot find any other engines apart from the 6A12 with the letter "A" after the first number.. what do they all mean?