1994 Chevrolet Cavalier Owner's Manual - Page 156

If you're using fuel rated at 87 octane or higher and you still hear heavy knocking, your engine needs service. But don't worry if you hear a little pinging noisewhen you're accelerating or driving up a hill. That's normal, and you don't have buy a higher octane to fuel to get rid of pinging. It's theheavy, constant knock that means you have a problem. What about gasoline with blending materials that contain oxygen (oxygenates),such asMTBE or alcohol? MTBE is "methyl tertiary-butylether." Fuel that is no more than 15% MTBE is fine for your vehicle. Ethanol is ethyl or grain alcohol. Properly-blended fuelthat is no more than 10%ethanol is fine for your vehicle. Methanol is methyl or wood alcohol. Fuel that is morethan 5% methanol is bad for your vehicle. Don't use it. Itcan corrode metal parts in your fuel system also and damage plasticand rubber parts. That damage wouldn't be covered under your warranty. And even at 5% or less, there must be "cosolvents" and corrosion preventers in this fuel to help avoid these problems. Gasolines for Cleaner Air Your use of gasoline with deposit control additives will help prevent deposits from formingin your engine and fuel system.That helps keep your engine in tuneand your emission control system working properly. It's good for your vehicle, you'll be and doing yourpart for cleanerair. Many gasolinesare now blended with oxygenates. General Motors recommends that you use gasolines with these blending materials, such as MTBE and ethanol. By doing so, you can help clean air,especially in the those parts of the country that have high carbon monoxide levels. In addition, some gasoline suppliersare now producing reformulated gasolines. These gasolines are specially designed to reduce vehicle emissions. General Motors recommendsthat you use reformulated gasoline.By doing so, you can help clean the air, especiallyin those parts of the country that have high ozone levels. You should ask your service station operators if their gasolines contain deposit control additives and oxygenates, and if they have been reformulated to reduce vehicle emissions.