Selecting the Right Octane
What are octane ratings?
Octane ratings measure a gasoline's ability to resist engine knock — a rattling or pinging sound that results from premature ignition of the compressed fuel-air mixture in one or more cylinders.
CountryMark offers gasoline in five octane grades: regular (87 octane), mid-grade (88, 89 and 90 octane), and premium (93 octane).
What's the right octane level for your car?
Check your owner's manual. Regular octane is recommended for most cars. However, some cars with high compression engines, like sports cars and certain luxury cars, need mid-grade or premium gasoline to prevent knocking.
How can you tell if you're using the right octane level? Listen to your car's engine. If it doesn't knock when you use the recommended octane, you're using the right grade of gasoline.
Will higher octane gasoline clean your engine better?
No, as a rule, high octane gasoline doesn’t outperform regular octane in preventing engine deposits from forming, in removing them, or in cleaning your car's engine. The best advice for avoiding and/or eliminating engine deposits is burning a TOP TIER gasoline.
Should you ever switch to a higher octane gasoline?
A few car engines may knock or ping even if you use the recommended octane. If this happens, try switching to the next highest octane grade. In many cases, switching to the mid-grade or premium-grade gasoline will eliminate the knock. If the knocking or pinging continues after one or two fill-ups, you may need a tune-up or some other repair.
A car's octane requirements can also change as mileage increases. As mileage accumulates, carbon deposits can form in the combustion chamber, which can increase the incidence of engine knock. Deposits raise the compression ratio and can get very hot, thus serving as a source of ignition.
Will knocking harm my engine?
Occasional light knocking or pinging won't harm your engine, and doesn't mean you need a higher octane. But a heavy or persistent knock can lead to loss of power, and overheating of engine parts such as valves, pistons and spark plugs. In severe cases, piston heads can crack or burn, and engine life can be shortened.
Where can I purchase CountryMark PLUS gasoline?
Visit our growing list of CountryMark retail fuel stations, or contact a CountryMark branded dealer to discuss fuel delivery options.