Vegetable oil, whether waste vegetable oil (WVO) or straight vegetable oil (SVO), can be used to run a diesel engine. It is way cheaper than diesel fuel and is an environment-friendly gas. But because vegetable oil is thicker than diesel fuel, diesel engine cannot burn it as fast as it burns diesel fuel. This is the reason vegetable oil has to be added to diesel. A tank can accommodate around 50% vegetable oil and 50% diesel fuel. In warmer climates, vegetable oil can even be increased to 80%. Adding vegetable oil to diesel fuel is simple to do, and here’s a guide you can follow.
- Collect vegetable oil. You can buy SVO from groceries or from the same companies that provide oil to restaurants. But if you want free oil, consider using WVO. This kind of oil is available for free at restaurants and other similar food establishments. These establishments will sure love to give you their waste oil because this saves them from paying waste collectors, so try to contact restaurants within your area and arrange for oil pickup schedule.
- Leave the oil for at least a week. Whether using WVO or SVO, leave the oil in its container for around one week. This will give the oil enough time to settle and the solid particles (in SVO) and food residues (in WVO) to float to the surface. In the end, you will have better and easier time to filter out the residues.
- Filter the vegetable oil. After about a week, your oil is ready to be filtered. Filtering can be done using a plastic strainer. Or you can also try using a thick piece of cloth as a filter tool like what others do. Some people find denim effective, so you may have to use an old pair of jeans for this. But whatever way you choose to filter the oil, make sure to properly and completely get rid of solid particles and food residues.
- Add the oil. When ready, you can add the vegetable into the tank. Slowly and carefully pour the oil to avoid spills. In case you make spills, you can use a dry towel to wipe them off.
Aside from adding vegetable oil to diesel fuel, you can also use twin tank engine systems as an option. The systems, as the name implies, have two tanks—one for diesel fuel and one for vegetable oil. The diesel fuel tank is set as the initial oil supplier. You can switch to vegetable oil tank after a few minutes by pressing a button. The vegetable oil has warmed up by this time and can be burned quite faster. Turn your switch again to diesel fuel if you are about to stop driving. This will keep the valves free of vegetable oil that is likely to solidify when the engine stops running. There are many companies that sell twin tank systems, but if you are technically adept, you can create your own system.