SERVICE GUILD: USE OF FUEL WITH 15% MTBE IN ALL GM VEH.

In August of 1988, the U.S. Environmental Protection Agency approved the use of methyltertiary-butyl ether (MTBE) in gasolines at concentrations of 15 percent or less. Prior to that time, the legal limit was 11 percent. Cadillac Owner's Manuals stated that the use of gasolines containing 11 percent or less MTBE should not adversely affect the operation of the vehicle and would be covered by the New Vehicle and Emission Control Systems warranties. The use of 15 percent MTBE in gasoline should also not adversely affect the operation of 1990 and earlier model vehicles; and therefore, will not void any warranties covering those vehicles. In the interest of contributing to cleaner air, Cadillac recommends that all model year vehicles use such fuels whenever available. The 1990 and future Owner's Manuals will reflect this position.

MTBE is not alcohol. Cadillac maintains its stance on alcohol-fuel blends:

As stated in Cadillac Owner's Manuals, properly blended fuel containing concentrations of no more than 10% ethanol is fine for Cadillac vehicles. More than this amount may deteriorate the rubber components in a vehicle's fuel system and void the vehicle's warranty.

Methanol can be safely used in fuel concentrations no more than 5%. Use of fuel with higher concentrations may corrode metal parts, deteriorate rubber components in a vehicle's fuel system, and will void the vehicle's warranty.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.