The Effect on Emissions and Emission Component Durability by the Fuel Additive Methylcyclopentadienyl Manganese Tricarbonyl (MMT) 912437

Vehicle emissions have been measured and the results statistically evaluated for a vehicle test fleet consisting of four Escorts and four Explorers using both methylcyclopentadienyl manganese tricarbonyl (MMT) at 1/32 gram Mn/gallon and clear (MMT free) fuel. The fleet was divided in half -- half with MMT and half without MMT doped fuel. This interim report covers emission measurement results at 5,000; 15,000; and 50,000 miles of exposure to MMT doped fuel. The planned mileage accumulation is for 100,000 miles of durability and exposure to MMT based fuel. A modified paired t-test is used to analyze the emission data obtained from all the fleet vehicles. The statistical evaluation of both feedgas and tailpipe emissions indicated that the use of MMT is detrimental to emissions of HC at both the 15,000 mile and 50,000 mile levels of MMT exposure. Indications also are as mileage is accumulated, the worse the effect on HC by MMT. CO tailpipe emission responses at 15,000 miles show a deleterious effect by MMT but a beneficial effect at 50,000 miles. All NO_x emission responses show a beneficial effect by MMT at the 15,000 mile level but all emission responses indicate a deleterious effect at 50,000 miles by MMT. Particulate emissions are described in a companion report. The physical and chemical characterization, as well as the final emission results, of emission components will be reported following completion of the program at 100,000 miles.