HC+NO2 would result in up to a 7% fuel penalty for diesel engines with a mid point of about 3%. For gasoline engines, the data also shows that the fuel penalty would be up to 17.5% with a mid point of about 9%. Meeting a 5 gm/BHP-HR HC+NO, standard would result in up to a 15% increase in fuel use for diesels with a mid point of 7%. The corresponding fuel penalty for gasoline engines would be up to 58% with a mid point of 27%.

As can be seen from the attached Figure 2 fuel consumption penalties vs. emission control levels, the fuel penalties grow at large and increasing rates as emissions are reduced. It should also be noted that we are not aware of any successful application of catalyst technology to either heavy duty gasoline or diesel engines.

Additional testimony at the CARB hearings revealed the probability of significant reductions in the number of engine families available for sale at the most stringent level. Some manufacturers reported that they would be unable to market any engines having overall satisfactory operating characteristics. Others would be restricted

to only one or two families. If heavy duty vehicle users face a more limited selection of engines to power their equipment, they will be less capable of specifying the optimal configuration for their application.

84-239 O - 77-34

FIGURE 2

At hearings of your Subcommittee on amendments to the Clean Air Act held February 9 and 10, the use of the antiknock compound MMT in unleaded fuels was discussed briefly. It was indicated by Senator Domenici that additional information relating to MMT would be considered by the Subcommittee. As the sole manufacturer of MMT, we are respectfully submitting the following information for the benefit of your Subcommittee and its Staff.

The petroleum industry is using MMT, an organo manganese compound, at low concentrations up to 0.125 gram of manganese

-

per gallon to increase the antiknock quality of unleaded gasoline.
Its use can increase road octane number by about two units. The
availability of MMT permits the production of the required quality
of unleaded gasoline with less severe refinery processing resulting
in significant energy savings since less crude oil is required. In
addition, the availability of MMT provides much needed flexibility
to the refiner. If all gasoline produced in the U. S. were unleaded,
the use of MMT would result in savings of about 58 million barrels
of crude oil per year, which is approximately two percent of projected
imported crude oil.

The Honorable Edmund S. Muskie
February 14, 1977
Page Two

The use of MMT in unleaded gasoline has been extensively investigated by Ethyl as well as by the automotive and petroleum industries. Our own programs, which were started in 1971, have included over 50 vehicles operated for over 2-1/4 million miles under a variety of driving conditions. In addition, thousands of hours of dynamometer testing of single-cylinder and multi-cylinder engines have been conducted. These intensive investigations are continuing.

The extensive testing of MMT has shown it to be compatible with satisfactory performance of catalytic control systems and engine components when used at recommended concentrations. Much of this testing has been conducted on recent production vehicles equipped with monolithic and pelleted catalytic converters. Under normal driving conditions, including the EPA durability test schedule, we have not experienced catalyst plugging, tailpipe emission increases of any significance or any spark plug problems within manufacturers' recommended change intervals.

Regarding the difficulties alleged to be related to MMT which were reported to the Subcommittee at the hearings last week, our experience would indicate that other factors may have been involved. To our knowledge, catalyst plugging as reported has never been experienced on MMT under certification-type testing. It has been observed only under unusually high exhaust temperature conditions or other abnormal operating conditions. While increases in engine-out hydrocarbon emissions have been noted in some cases, tailpipe hydrocarbon increases have not been found to be significant. Spark plug problems have not been encountered at mileages less than manufacturers' recommended life, and, in fact, some vehicles have operated satisfactorily for 50,000 miles on the original plugs with fuels containing MMT at the 0.125 Mn/gal level. Reported per

Senator Edmund S. Muskie

February 14, 1977
Page Three

formance of three-way catalyst systems including oxygen sensors

on MMT-containing fuels has been satisfactory.

While we are not familiar with all the details of the recently alleged problems attributed to fuels containing MMT, it would appear that, based on the experience accumulated to date, complete researching of the problems should result in solutions which would not restrict the energy extending benefits of MMT.

Attached are our detailed comments relating to all aspects of the use of MMT. Should there be any questions regarding this material or any other aspects of the use of MMT, we will be glad to respond.

Very truly yours,

HEH:sc

Att.

H. E. He's selberg