Abstract: The diesel fuel gauge is used for determining the level of diesel fuel in a diesel fuel tank. The gauge is in the form of an elongated member formed of white plastic material with spaced apart marks and numbers formed on one side of a gauge portion with a handle extending from the gauge portion. A dry layer of material soluble in diesel fuel coats the side of the gauge covering the marks and numbers. The material in one embodiment includes asphalt mixed with a liquid thinner and a liquid drying agent. When the gauge is inserted into the diesel fuel in the tank and removed, the material in contact with the diesel fuel may be removed from the member by wiping it off to expose the marks and numbers for use for determining the level of diesel fuel in the tank.