1993 Buick Skylark Owner's Manual - Page 218

Fuel Use regular unleaded gasoline rated 87 octane or at 14 higher. It should meet specifications ASTM D48 in the U.S. and CGSB 3.5-92 in Canada. These fuels so should have the proper additives, you should not have to add anything the fuel. to In the U.S. and Canada, it's easy to be sure you get the right kind of gasoline (unleaded).You'll see "UNLEADED" right on the pump. And only unleaded nozzles will fit into your vehicle's filler neck. Ethanol is ethyl or grain alcohol. Properly-blended fuel 10%ethanol isfine for your that is no more than vehicle. Methanol is methyl or wood alcohol. 87. Be sure the posted octane is at least If the octane is less than 87, you may get a heavy knocking noise when you drive. If it's bad enough,it can damage your engine. If you're using fuel rated 87 octane or higher and you at still hear heavy knocking, your engine needs service. But don't worry if you hear little pinging noise when a you're acceleratingor driving up a hill. That's normal, and you don't have to buy a higher octane fuel to get rid of pinging. It's the heavy, constant knock that means you have a problem. What about gasoline with blending materials that contain oxygen, such MTBE or alcohol? as MTBE is "methyl tertiary-butyl ether." Fuel thatis no more than 15% MTBE is fine for your vehicle. Gasolines for Cleaner Air Your use of gasoline with detergent additives will help prevent deposits from forming in your engine and fuel system. That helps keep your engine in tune and your emission control system working properly. It's good for your vehicle, and you'll be doing your part for cleaner air. Many gasolines are now blended with materials called oxygenates. General Motors recommends that you use 217