| Vehicles fitted with advanced emission control systems performed well with MMT® |
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All of the test vehicles met applicable emission standards. |
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Catalytic converters, spark plugs, oxygen sensors and OBD-II systems performed as designed. |
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MMT® had no negative effect on vehicle fuel economy. |
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Test results are consistent with previous fleet test results: MMT® does not cause the failure of emission control devices or an increase in vehicle pollutants. |
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The study confirms Ethyl’s view that MMT® protects emission control systems from phosphorus and sulfur combustion debris that can degrade catalysts and components. |
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Oxygen sensor and catalyst conversion performance was indicative of the established
MMT® scavenging mechanism for phosphorus and sulfur. |
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The air-fuel ratio in the MMT®-fueled vehicles remained closer to the original design and the reported fleet emissions trends are consistent with the greater lean shift experienced by the base-fueled vehicles. |
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The MMT®-fueled vehicles performed well despite numerous flaws in the study design and questionable maintenance practices |
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The study did not follow the fleet testing protocols endorsed by the auto industry in previous studies and ignored most of the recommended changes made by reviewers. |
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The extreme driving cycle used in the study reflects accelerated aging conditions. The driving cycle had double the aging factor compared to severe consumer driving (95th to 99th percentile). |
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The AAM engaged in questionable maintenance practices that included performing major repairs on a base-fueled vehicle and not on its MMT®-fueled partner vehicle and failing to perform maintenance on MMT®-fueled vehicles with significant mechanical problems. |
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The low emission vehicles assigned to run on MMT®-fuel had lower fuel economy and higher CO2 emissions than the base-fueled vehicles before any mileage accumulation on the test fuels. This initial bias was maintained throughout the course of the study and suggests that the two fleets were fundamentally different. |
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An independent statistical review by Environ supports Ethyl’s assessment |
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The performance of vehicles using MMT® -fuel was not statistically different from the performance of vehicles using base-fuel. |
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The AAM’s conclusions are based on flawed and inappropriate statistical analysis. |
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The AAM’s analysis ignores confounding variables and incorrectly attributes all differences in emission performance to the presence of MMT®. |
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Vehicle design and variability dwarf all other factors impacting vehicle emissions. |