2013 Chrysler 300 Owner Manual SRT - Page 442

440 STARTING AND OPERATING FUEL REQUIREMENTS 6.4L Engine The 6.4L engine is designed to meet all emissions regulations and provide excellent fuel economy and performance when using high-quality premium unleaded gasoline with an octane rating of 91 or higher. 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 before considering service for the vehicle. Over 40 auto manufacturers worldwide have issued and endorsed consistent gasoline specifications (the Worldwide Fuel Charter, WWFC) which define fuel properties necessary to deliver enhanced emissions, 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." 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.