Q: At the last place I had my oil and filter changed, I was told I should come back after driving another 3,000 miles or three months, whichever comes first. Is that really necessary? I have a 2009 Ford Explorer SUV.
A: This recommendation is actually a carryover from years ago, before engines were built to today’s exacting standards.
Today, the fuel and ignition systems and, in some cases, the engine camshafts, are controlled by sophisticated computer controls that contribute to a longer life for engine lubricants. Many of the lubricants are also built to much higher standards.
The three jobs of the engine oil are to lubricate the moving parts, carry heat away from the moving parts and carry any debris away from the moving parts to the engine oil filter.
The higher quality of many of today’s engine oils allows them to lubricate the moving parts for a longer period of time and carry heat away with a slower degradation of the oil. Both the computer controls and the higher mechanical standards of the engine reduce the amount of debris the oil has to contend with. The debris is mainly the product of the combustion process that takes place in the engine and gets past the pistons into the bottom part of the engine where the oil resides.
Why does this make a difference in the oil-change interval? How frequently do today’s engine oils and filters need to be changed?
It differs depending on the type of oil – petroleum- or synthetic-based. Generally, petroleum should be changed every 5,000 miles or every five months. For top-of-the-line synthetic-based oils, change intervals can be as long as 25,000 miles or one year.
The type of driving also influences how often the oil should be changed. Many of the new vehicles have a computer program that alerts you when an oil change is necessary based on engine speed, miles driven and how hard the engine has been working (i.e., acceleration, driving up hills, etc.).
Also, please note that even with the improved oil and filters available, just as with any other product, there is still a varying degree of quality, and your vehicle may require a specific oil and filter (check your owner’s manual). So it is important that whoever is changing your oil and filter uses the correct and proper quality products. Using the wrong oil and/or filter can cause the engine to fail prematurely.
Many manufacturers require that their engines and drivetrains use synthetic lubricants, and the vehicles come from the factory with those synthetic lubricants. Therefore, the recommended change interval is based on the quality of that lubricant.
A few years ago, a vehicle manufacturer filled its engines with synthetic lubricants and recommended a long duration change cycle. The dealerships followed the recommended interval but used petroleum-based lubricants instead of synthetics. That resulted in damage to the engines. After losing a lawsuit, the manufacturer had to cover the damaged engines under warranty.
Choosing the lowest-priced oil increases the risk that you may compromise the quality of the products being used on your car. At first, there may not be any apparent difference in your vehicle’s performance, but over the life of your vehicle, those cheap oil changes using the wrong or lower-quality products could cost you thousands of dollars in repairs.