1. Gasoline Engines

Reformulated gasolines (RFG) and/or unleaded gasoline containing oxygenates such as Ethanol, TAME, ETBE, IPA, IBA and TBA can be used provided that the ratio of any one of these oxygenates to gasoline does not exceed 10 percent. MTBE may be added up to 15 percent. The ratio of Methanol to gasoline must not exceed 3% plus additional co-solvents.

Mixtures of Ethanol and Methanol must not be used. Gasohol, which contains 10% Ethanol and 90% unleaded gasoline, can also be used. These blends must also meet all other fuel requirements such as resistance to spark knock, boiling range, vapor pressure, etc.

Gasoline Additives

A major concern among engine manufacturers is carbon build-up caused by gasoline. MERCEDES-BENZ recommends to use only 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.

DO NOT blend other fuel additives with the fuel. These additional additives only result in unnecessary cost and may be harmful to engine operation.

Damages or malfunctions resulting from poor fuel quality or from blending additional fuel additives are not covered by the MERCEDES-BENZ Limited Warranty.

For model year 1986, all gasoline models except 190 E 2.3 require premium unleaded gasoline.
As of model year 1987, all gasoline engines require premium unleaded gasoline

Use only premium unleaded gasoline meeting ASTM standard D439. The octane number posted at the pump must be at least 91 min. In the U.S., this octane number is an average of the Research octane number (R) and the Motor octane number (M): (R + M) / 2. The octane number is also known as the Anti-Knock Index.

CAUTION! To maintain the engine's durability and performance, only premium unleaded gasoline is to be used. If premium unleaded is not available and low octane gasoline is used, follow these precautions:

- Partially fill the fuel tank 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 2000 rpm if the vehicle has a light load (two occupants and no luggage for example).
Do not exceed 2/3 of maximum accelerator pedal position if the vehicle is fully loaded or operating in mountainous terrain.

Model years 1975 - 1985 and model year 1986 model 190 E 2.3

Use unleaded regular gasoline meeting ASTM standard D439. The octane number posted at the pump must be at least 87 min.

Model years 1972 - 1974

Use leaded or unleaded~gasoline meeting ASTM standard D439. The octane number posted at the pump must be at least 87 min. When only unleaded gasoline is being used, check the valve clearance on engines with mechanically adjustable valves at half the recommended interval.

Pre-model year 1972

Use premium unleaded gasoline meeting ASTM standard D439. The octane number posted at the pump must be at least 91 min. Check the valve clearance at half the recommended interval.