I saw this recently and am curious what it's all about. I understand the Top Tier fuel specifications, but what exactly is MMT. Who has it in their fuel stocks ( Shell, Mobil, ConocoPhillips)? What is the effect to our stock Fiero engines, long and short term? Read below and let us know what you think.


"Some gasoline in North America contains MMT, a manganese-based fuel additive. Prolonged and consistent use of gasoline containing MMT can deteriorate your vehicle's performance, fuel economy, and the emission control system. Always use MMT -free gasoline if available. Failures caused by use of gasoline containing MMT may not be covered under your new vehicle warranty.

TOP TIER Detergent Gasoline (recommended) never contains MMT and has detergent additives to keep your engine clean. For further information on fuel and lubricants for your car and information on gasoline that does not contain MMT, contact your dealer"

Wikipedia:
Methylcyclopentadienyl manganese tricarbonyl (MMT or MCMT) is an organomanganese compound with the formula (CH3C5H4)Mn(CO)3. Marketed as a supplement to the gasoline additive tetraethyllead to increase a fuel's octane rating, MMT was later used in unleaded gasoline. Following the implementation of the Clean Air Act (United States) (CAA) in 1970, MMT continued to be used alongside TEL in the US during the phase-out of leaded gasoline (prior to TEL being finally banned from US gasoline in 1995) and was also used in unleaded gasoline until 1977. Ethyl Corporation obtained a waiver from EPA in 1995. The waiver allows the use of MMT in US unleaded gasoline (not including reformulated gasoline) at a treat rate equivalent to 8.3 mg Mn/l.[2]

MMT has been used in Bulgaria, France, Argentina and in Canadian gasoline since 1976 at a concentration up to 18 mg Mn/l (though the importation and interprovincial trade of gasoline containing MMT was restricted briefly during the period 1997-1998)[3][4] and was introduced into Australia in 2000. It is sold under the tradename HiTEC® 3000.[5] It was also marketed as Ecotane by T2 Labs

Now why would a manufacture say it could damage its engines? How about our Fieros? How about if a fuel manufacturer is using MMT to boost its octane rating what might they be leaving out of the fuel to require the use of MMT in the first place? Just curious.

[This message has been edited by Kevin87FieroGT (edited 12-09-2015).]

Maybe it's a case of non top-tier gas will leave "harmful" deposits (carbon and such) that can screw up your engine, long-term. In other words, it isn't the MMT that's a problem so much as the sub-par gas it's put in. Just a guess, though!

From a manufacturer of MMT. Sounds harmless. Makes it all good for the refiner and vehicle owner. Right.

https://www.aftonchemical.c...l/HiTEC-3000_PDS.pdf