Many owner-operators and fleet managers are aware of the fuel savings associated with lower viscosity engine oil, but they may not know what exactly it does to improve performance and help drivers save money. The lower viscosity of low-ash oil allows it to move more freely throughout the engine, promoting better lubrication and cooling. This in turn reduces fluid friction and helps the engine run more efficiently, increasing fuel economy.

The numbers printed on the side of a can of engine oil, such as “5W-30,” indicate the viscosity of the oil. The first number indicates the low-temperature viscosity; the number after the letter “W” is the winter/cold testing rating. The grading system was established by the Society of Automotive Engineers (SAE). Oils that meet both low and high-temperature demands are identified by a number with no letter following the SAE viscosity grade (example: multi-viscosity, 10W-40).

When choosing an engine oil, it is important to remember to select the correct one for your vehicle’s working conditions and environment. It is also a good idea to follow the recommendations made by the OEM for maximum engine performance and to protect your warranty. If you are unsure of which engine oil is right for your truck, consult the owner’s manual or a certified mechanic.