On the one hand, it improves the lubricity of diesel fuel, which is useful for the operation of the vehicle’s fuel equipment. On the other hand, sulfur, burning in the engine together with diesel fuel, oxidizes, reacts with water vapor, which is also one of the products of hydrocarbon combustion, and turns into acid. The latter eventually ends up in the engine oil. We suppose there is no need to explain what problems the presence of a strong acid in the lubricant threatens to the engine parts.
Read more: https://thegoaspotlight.com/2021/10/27/why-do-experienced-car-owners-pour-diesel-engine-oil-into-a-gasoline-engine-lifehack/