1995 Chevrolet Corvette Owner's Manual - Page 239
1995 Chevrolet Corvette Manual
Page 239 highlights
Gasolines for Cleaner Air Your use of gasoline with deposit controladditives will help preventdeposits 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 oxygenates. General Motors recommends that you use gasolines with these blending materials, such as MTBEand ethanol. By doing so, you can help cleanthe air, especially in those parts of the country that have high carbon monoxide levels. In addition, some gasoline suppliers arenow producing reformulated gasolines. These gasolinesare specially designed toreduce vehicle emissions. General Motors recommends that you use reformulated gasoline. By doing so, you can help clean the air, especially in those parts of the country that have high ozone levels. You should askyour service station operators if their gasolines contain deposit control additives and oxygenates, and if they have been reformulated to reduce vehicle emissions. 5.7L LT1 (Code P) Engine Use premium unleaded gasoline rated at 91 octane or higher for best performance. You may use middle grade or regular unleaded gasolines, but your vehicle may not accelerate as well. The gasoline you use should meet specifications ASTM D4814 in the United States and CGSB 3.5-92 in Canada. These fuels should have the proper additives, so you should not have to add anything to the fuel. In the United States 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 intoyour vehicle'sfiller neck. Be sure the posted octane for premium is at least 91 (at least 89 for middle grade and 87 for regular). If the octane is less than 87, you may get a heavyknocking noise when you drive. If it's bad enough, it can damage your engine. If you're using fuel rated at 91 octane or higher and you still hear heavy knocking, your engine needs service. But don't worry if you hear a little pinging noise when you're accelerating or 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. 6-4