To find out what octane your engine needs, first check your owner's manual. The recommended level is often 87 octane. Some high compression engines are designed to utilize levels of 89, 91 or higher.
Ordinarily, your vehicle will not benefit from using a higher octane than is recommended in the owner's manual. But if your engine knocks or pings at the recommended octane level, you may need a higher octane gasoline to prevent the knock. Knocking may occur under certain conditions, such as unusual engine deposits, extremely hot weather, and or hard driving conditions (towing a heavy load).
