2009 Dodge Avenger Owner Manual - Page 325

STARTING AND OPERATING 323 FUEL REQUIREMENTS 2.4L and 2.7L Engine The 2.4L and 2.7L engines are designed to meet all emission regulations and provide excellent fuel economy and performance when using high quality unleaded "regular" gasolines having an octane rating of 87. The use of premium gasoline is not recommended. Under normal conditions, the use of premium gasoline will not provide a benefit over high quality unleaded "regular" gasolines, and in some circumstances may result in poorer performance. 3.5L Engine The 3.5L 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 89. The manufacturer recommends the use of 89 octane for optimum performance. The use of premium gasoline is not recommended. Under normal conditions, the use of premium gasoline will not provide a benefit over high quality unleaded "regular" and "mid-grade" 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. 5