Why is the 3000 mile change still recommended?
For over 40 years, domestic manufactures have not recommended it. Then what about
5000-7500 miles? The current recommendation, or the OIL Life Monitor system used by some manufacturers, monitors computer data to determine when it is most likely due to be changed. The more reliable way to tell if oil is ready to be changed is a UOA (used oil analysis) something very few people are aware of.
One thing that is sure, automobile engine oil still must be changed to optimize the life and functionality of any internal combustion engine. Dirty oil does not lubricate properly.
In the "early days", experience and expertise was the guiding factor as to when the oil was changed. We were taught that by three thousand miles, given the oil and engine quality, a car needed an oil change. Premature engine wear and failure was common. Most had no filtration. This was because in the early days quality of engines and oils were sub-standard. And unwanted wear began at or about this point so the oil needed to be changed. It was the universally accepted truth in the day.
Fast forward to modern times. Automotive oil changes are still based on a number of factors we all accept as true because someone said so. Fact: oil should be changed regularly. This ensures a reasonable amount of wear to keep the family truckster going strong for a required number of years.
Miles between oil changes is still the general indicator used for when to change oil. But what happens between changes should also be considered. First, the quality of the oil. Just like everything else in life there are some good, some better and then the best. Second, the condition of the engine at the time of the change. Are the bearings and bushings perfect or worn? Is there any fuel or coolant contamination present? Unless it is excessive you or your mechanic won't know. Third, one driver will definitely drive the vehicle harder than the next, making greater demands of the engine. Fourth, how about the gasoline used. Poor or low quality of fuel and the conditions it is stored under.
All these factors make changing your oil a crap shoot at best, even though today's modern engines will take much more abuse than in the past.
Some manufacturers have a system to try to remove some of the variables by developing what is called, OIL LIFE Monitor.It is okay in the way it monitors the engine and some engine operating parameters, IE; throttle position, oxygen sensors, up and down stream, and other engine controls. OLM, as it is known, starts with a basic flaw, assumptions must be made about the engine condition. It has no way to tell if a top synthetic like AMSOIL or big Al's bulk was used at the time the oil was changed.What about filtration? Again some better than others. Also, it has been my experience that none of the OLM systems will go beyond 10K before alerting a change is needed.
UOA is the ONLY way to tell if an automobile engine needs the oil changed, And any other is just a " WILD GUESS" based on miles or a computer system. Entirely too much automobile engine oil is being replaced unnecessarily.
The quality of engine oil has improved along with engine technology. Oil changes can be extended and engine problems identified before they cause premature engine wear. We can drastically reduce oil and filter waste, save time, money and the environment. Next time you think your engine oil is due to be changed think about UOA, you'll be glad you did. Use a high quality engine oil and UOA for the best results in determining when to change.