2009 Chrysler Town & Country Owner Manual - Page 387

STARTING AND OPERATING 385 4.0L Gasoline Engine This engine is designed to meet all emissions regulations and provide satisfactory fuel economy and performance when using high-quality unleaded gasoline having an octane range of 87 to 89. The manufacturer recommends the use of 89 octane for optimum performance. The use of premium gasoline is not recommended, as it will not provide any benefit over regular gasoline in these engines. Over 40 automobile manufacturers around the world have issued and endorsed consistent gasoline specifications (the World Wide Fuel Charter, WWFC) to define fuel properties necessary to deliver enhanced emissions, engine performance, and durability for your vehicle. The manufacturer recommends the use of gasolines that meet the WWFC specifications if they are available. Reformulated Gasoline Many areas of the country require the use of cleaner burning gasoline referred to as "Reformulated Gasoline". 5 Light spark knock at low engine speeds is not harmful to Reformulated gasolines contain oxygenates, and are speyour engine. However, continued heavy spark knock at cifically blended to reduce vehicle emissions and imhigh speeds can cause damage and immediate service is prove air quality. required. The manufacturer supports the use of reformulated gasoPoor quality gasoline can cause problems such as hard lines. Properly blended reformulated gasolines will prostarting, stalling and hesitations. If you experience these vide excellent performance and durability of engine and symptoms, try another brand of "regular" gasoline befuel system components. fore considering service for the vehicle.