MMT (methylcyclopentadienyl manganese tricarbonyl) is an antiknock additive for the unleaded gasoline that is now required for cars equipped with catalytic converters. Because of its effectiveness, MMT is economically attractive compared with achieving antiknock quality by refinery processing.
This paper updates an earlier SAE paper. Whereas the earlier paper evaluated all aspects of MMT use as an antiknock, this paper is primarily limited to analysis of the possible effects of MMT on exhaust emissions, catalyst plugging, and spark plug life. The results of recent tests and a report on a fleet test currently in progress are included.