1993 Oldsmobile Silhouette Owner's Manual - Page 219

If you're using fuel rated at 87 octane or higher and you still hear heavy knocking, your engine needs service. Fuel But don't worryif you hear a little pinging noise when you're accelerating Use regular unleaded gasoline ratedat or driving up a hill. That's normal, and 87 octane or higher. It should meet you don't have to buya higher octane specifications ASTM D4814 in the U.S. fuel to get ridof pinging. It's the heavy, and CGSB 3.5-92 in Canada. These constant knock that means you have a fuels should havethe proper additives, so you should nothave to add anything problem. to the fuel. What about gasoline with blending materials that contain oxygen, such as In the U.S. and Canada, it's easy to be MTBE or alcohol? sure you get the right kind gasoline of (unleaded). You'll see "UNLEADED" MTBE is "methyl tertiary-butyl right on the pump. And only unleaded ether:' Fuel that is no more than 15 % nozzles will fit into your vehicle's filler MTBE is fine for your vehicle. neck. Ethanol is ethyl or grain alcohol. Be sure the posted octane at least 87. is Properly-blended fuel thatis no more If the octane is less than 87, you may get than 10%ethanol is fine for your a heavy knocking noise when you drive. vehicle. If it's bad enough, itcan damage your Methanol is methyl or wood alcohol. engine. Fuel Capacity: 20 U.S. Gallons (76L). Use unleaded fuel only. 227