Does synthetic oil buy me time?

  • James Halderman
12:00 a.m. Friday, Sept. 1, 2017 Cars
All vehicles built by General Motors should use engine oil that meets the Dexos standard. Oil should be changed when the oil life monitor indicates that it time to do so. James Halderman photo

Wheels: Jim of Centerville asks: “I own a 2014 Chevrolet Impala and I was wondering if I used synthetic engine oil, can I delay the oil change interval? My car shows the life of the oil in percent and often shows a message to ‘change oil soon’ after just six months of driving. I would rather delay the need to change the oil to once a year so I don’t have to visit a shop as often.”

Halderman: The short answer is no. Your General Motors vehicle requires the use of Dexos certified engine oil; this specification, which is available from many different oil brands, is formulated to meet the needs of your engine.

According to GM, the oil life monitor should be used as your guide to change the oil regardless of the type of oil used. When the OLM is reset after the oil has been changed, the Powertrain Control Module monitors the operation of the engine and the number of starts and subtracts a percentage from 100 as determined by the level of harm that the oil may experience.

For example, a cold start when the temperature is below freezing may cause the PCM to subtract 1 number, whereas it may require a long trip at highway speed to subtract the same one point. In other words, the time and miles it takes for the PCM to count down to about 15 percent and show the message to “change the oil soon” varies as to how the vehicle is driven. Short trips and city driving will cause the oil to be changed more often compared to those who drive many miles at highway speed over long distances.

The bottom line is to use the specified engine oil and change the oil when the oil life monitor indicates that it is time to change the oil.

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