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Should Synthetic Oil Darkening in Color be Changed?
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Should Synthetic Oil Darkening in Color be Changed?
I own a 5.4 liter Ford engine with 90,000 miles. I purchased it with 87,000 miles and at that time chose to use Mobil 1. I've run the Mobil 1 in this engine for 3,000 miles and my oil appears to be "black" in color. I have a few thoughts as to why this is occurring but thought I would ask the experts. This particular product is supposed to have a life of 15,000 miles or 1 year if my memory serves me correctly, but the way it looks I'm tempted to change it and put in fresh Mobil 1. Do you have a recommendation? I'm curious as to what's taking place here and willing to correct it if necessary, Thank You
-- Gary Faupel, St. Louis, MO
We would never use color alone as an indication to gauge whether or not you should change your motor oil. Without oil analysis you can reach the wrong conclusion about oil quality and in many cases darker engine oil is not a sign of any issue or problem. Some additives used in modern oils can produce a dark color over time and this is normal. It is best to change your oil based on time in months or miles. Of course, the number of miles and months depends on many things like service, climate, engine condition, etc. It may be possible in your case that the color could be indicating that since this is the first time the engine may have seen Mobil 1™ synthetic oil, that the strong additive package is doing some clean-up in your engine. Do you know what kind of service this engine received? To be safe we would use a shorter drain interval in your vehicle for a couple of Mobil 1 oil changes, and gradually extend the drain interval as you go to the drain interval you feel most comfortable with.
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