Why Do I Have to Top-Off Oil in My Engine?

Most of you probably check your oil level each day or when you fill your fuel tank. A low oil level can lead to faster oil degradation (oxidation), faster oil consumption, and potentially shorter engine life.

When discussing the issue of oil consumption, we must keep in mind that there are only two ways oil is consumed in a diesel engine: Oil is either burned in the combustion chamber, or it leaks through seals or gaskets.

Several factors or conditions can affect the amount of oil an engine consumes. Some of the factors that affect oil consumption include engine idle time, driving conditions, load, terrain, engine operating temperature, oil volatility, fuel dilution, and miles on the engine. Another important point to remember is that no two engines are alike.

You may have noticed that late-model trucks use less engine oil. New oils control piston deposits, which results in better oil consumption control. Newer piston and piston ring designs, along with changes in engine operating conditions, are also factors.

Oil formulation can help provide the best oil consumption control. Premium motor oils are formulated to exceed the most current requirements of all North American truck engine manufacturers as well as those of the American Petroleum Institute. All Shell Rotella^® engine oils are formulated with a careful balance of detergent, dispersant, anti-oxidant and anti-wear chemistry that qualifies them to be used in extended service. Extensive field testing has further documented their exceptional performance.

Adding a gallon of oil every few thousand miles was once common. We now see late model engines that will go an entire drain interval without requiring additional oil. However, we still recommend checking your oil daily and topping off as required.

To further help monitor conditions in your engine, we recommend having an oil analysis program. It is one of the most effective ways to monitor the condition of your engine. A regular oil analysis program helps you build a historic database and watch for trends in a variety of areas. Ideally, you want to analyze a sample of used engine oil after every oil change.

Oil analysis through Shell LubeAnalyst can help to optimize oil change intervals, which can help drivers ensure maximum protection of their engines and have the peace of mind that comes with taking the guesswork out of oil changes.