A longer-term solution will require a much more comphrensive approach. MTBE should be phased out as a gasoline additive as soon as possible. California is on track to have a phase out by December 2002. A national phase out should occur on a similar timetable. It is used to raise octane levels.
Motor vehicles require a minimum octane level to operate properly.
MTBE has been used as a replacement for tetraethyl lead when that substance was banned as a fuel additive to increase octane levels. The phase out and eventual prohibition of adding tetraethyl lead to gasoline was responsible for a major improvement of public health and the environment. An alternative solution that avoids the need for such additives is to promote the use of vehicles that do not require high octane fuels. It should be noted that using a fuel with a higher-octane level than the minimum recommended by the manufacture generally does not improve engine performance. MTBE is also used as an oxygenate to make the gasoline burn cleaner and reduce tailpipe air emissions.