2005 Mercedes E-Class Owner's Manual - Page 468

Technical data Fuels, coolants, lubricants etc. Fuel requirements Gasoline engine Only use premium unleaded gasoline meeting ASTM standard D 439. The octane number (posted at the pump) must be 91 "min". It is an average of both the Research (R) Octane Number and the Motor (M) Octane Number: (R+M)/2). This is also known as the ANTI-KNOCK INDEX. Unleaded gasoline containing oxygenates such as ethanol, IPA, IBA and TBA can be used provided the ratio of any one of these oxygenates to gasoline does not exceed 10%; MTBE must not exceed 15%. The ratio of methanol to gasoline must not exceed 3% plus additional cosolvents. Using mixtures of ethanol and methanol is not allowed. Gasohol, which contains 10% ethanol and 90% unleaded gasoline, can be used. These blends must also meet all other fuel requirements, such as resistance to spark knock, boiling range, vapor pressure, etc. Diesel engine Only use commercially available vehicular diesel fuels No. 2 or No. 1 (ASTM D975 No.2-D or No.1-D). To prevent malfunctions, diesel fuel with better cold flow quality is offered in the winter months. Check with your fuel retailer. Coolants The engine coolant is a mixture of water and anticorrosion/antifreeze, which provides: Corrosion protection Freeze protection Boiling protection (by increasing the boiling point) The cooling system was filled at the factory with a coolant providing freeze protection to approximately -22°F (-30°C) and corrosion protection. ! Do not fill the tank with gasoline. Do not mix diesel fuel with gasoline or kerosene. The fuel system and engine will otherwise be damaged, which is not covered by the Mercedes-Benz Limited Warranty. 466