2008 Mercedes C-Class Owner's Manual - Page 482

Technical data Fuels, coolants, lubricants, etc. Premium unleaded gasoline Warning! G ! To maintain the engine's durability and performance, premium unleaded gasoline must be used. If premium unleaded gasoline is not available and low octane fuel is used, follow these precautions: Have the fuel tank only partially filled with unleaded regular gasoline and fill up with premium unleaded gasoline as soon as possible. Avoid full throttle driving and abrupt acceleration. Do not exceed an engine speed of 3000 rpm if the vehicle is loaded with a light load such as two persons and no luggage. Do not exceed 2/3 of maximum accelerator pedal position if the vehicle is fully loaded or operating in mountainous terrain. Gasoline additives A major concern among engine manufacturers is carbon build-up caused by gasoline. Mercedes-Benz recommends only the use of quality gasoline containing additives that prevent the build-up of carbon deposits. After an extended period of using fuels without such additives, carbon deposits can build up especially on the intake valves and in the combustion area, leading to engine performance problems such as: Warm-up hesitation Unstable idle Knocking/pinging Misfire Power loss Gasoline is highly flammable and poisonous. It burns violently and can cause serious personal injury. Never allow sparks, flame or smoking materials near gasoline! Turn off the engine before refueling. Whenever you are around gasoline, avoid inhaling fumes and skin or clothing contact, extinguish all smoking materials. Direct skin contact with fuels and the inhalation of fuel vapors can damage your health. 481