2008 Jeep Patriot Owner's Manual - Page 313

STARTING AND OPERATING 311 FUEL REQUIREMENTS GASOLINE ENGINES Your vehicle is designed to meet all emission regulations and provide excellent fuel economy when using high-quality regular unleaded gasoline with an octane rating of 87. The use of premium gasoline is not recommended. The use of premium gasoline will provide no benefit over high-quality regular gasolines and, in some circumstances may result in poorer performance. Light spark knock at low engine speeds is not harmful to your engine. However, continued heavy spark knock at high speeds can cause damage and immediate service is required. Poor quality gasoline can cause problems such as hard starting, stalling and hesitations. If you experience these symptoms, try another brand of gasoline (with the appropriate octane rating for your engine) before considering service for the vehicle. Reformulated Gasoline Many areas of the country require the use of cleaner burning gasoline referred to as "reformulated gasoline". "Reformulated gasolines" contain oxygenates and are specifically blended to reduce vehicle emissions and improve air quality. The manufacturer supports the use of "reformulated gasolines". Properly blended "reformulated gasolines" will provide excellent performance and durability of engine and fuel system components. 5