How Do I Mix Used Motor Oil with Diesel Fuel?

The process of mixing used motor oil with diesel fuel is actually very simple. The first thing you need to consider is the cleanliness of the used oil you want to use. Be sure that it is stored in a clean container, and closely observe the oil for signs of water and antifreeze. Neither of these liquids will mix with the oil, so they should be very visible to the naked eye. If your oil is contaminated with either and any type of engine rust, you will not be able to use it.

Once you have determined that you are using a generally uncontaminated supply of used oil, you need to filter it. An ordinary paint filtering system works well. Use a large (10 to 20 gallons) bucket, and slowly pour the oil into it. The filtering system will remove most of the impurities and smooth out the texture of the oil.

Now you are ready to mix your oil with the diesel fuel. The first time you attempt to use oil in your vehicle, mix only about 10 percent oil with about 90 percent diesel fuel. The limit to how much oil your vehicle can comfortably run on will grow, but you need to wean it to the new fuel mixture. You can listen to the engine and check the smoke coming out of the tailpipe to determine how your vehicle is handling the transition. If the engine is a good deal louder than usual, making clanking sounds or producing a black exhaust, then you need to dial down the amount of oil you are using.

Gradually up the oil content to an 80/20 mixture. Monitor your vehicle’s performance, as every engine adjusts differently. Many automobiles are capable of running mixtures all the way up to 50/50 after a great deal of progression.

Do some research on your vehicle to see how other owners have fared with running oil in their engines. The sites listed in the Resources and References sections of this article have forums where you can interact with other drivers who are operating with oil/diesel mixtures. You results may not always match theirs, but it gives you a good template of what to expect in terms of performance. If you find that your vehicle is not running as efficiently, speed or power is degenerating or the engine is running loudly and burning dirty exhaust, you need to reevaluate your mixture.