How many gals of oil in a semi tractor?

Typically, a semi-tractor (also known as a semi-truck or 18-wheeler) requires between 18 to 22 gallons (68 to 83 liters) of engine oil. However, the exact amount of oil needed may vary depending on the specific make, model, and engine size of the semi-tractor. It's always recommended to refer to the owner's manual or specifications provided by the manufacturer for accurate information on the oil capacity of a particular semi-tractor.