Acid eats the bearings too, pitting them, causing the rear to whine/growl. I'd go slightly more often.https://www.mustang6g.com/forums/threads/2015-v6-auto-diy-transmission-oil-filter-change.115392/
Rear differential - unlike the AWD, this diff doesn't have clutches so oil should be good for life, but will change it for a top grade at 100K miles
The color of engine oil has nothing to do with it's quality. A recent oil change using new oil with only a few hundred miles and 3-4 heat cycles will turn dark very fast, but it will still be very, very good oil.If it hasn't been 5k miles, but your oil is black, change it.
The color of your sample vs the color of the sample after just a paper chromatography test can vary greatly, that's why you always go by the color on the paper towel after you wipe the dipstick.The color of engine oil has nothing to do with it's quality. A recent oil change using new oil with only a few hundred miles and 3-4 heat cycles will turn dark very fast, but it will still be very, very good oil.
I have sent oil samples of my used Mobil 1 5w-40 to BlackStone labs where the oil was as black as coal with only 4K miles on it, and the lab stated that my oil change interval could be easily be stretched out to 7.5K - 8K miles based on their analysis.
On large machinery, where an oil change can cost $1000+ and take an expensive machine out of service for awhile, the owners often use oil analysis. When it is 10 quarts, a $6 filter, and down time has little to no cost, I agree: change it if there is any question. Oil analysis can tell us if the air filter is working properly, changing oil won't reveal that (but a new air filter is probably less $$ than analysis).The color of your sample vs the color of the sample after just a paper chromatography test can vary greatly, that's why you always go by the color on the paper towel after you wipe the dipstick.
Not trying to start an argument, but changing fluids is never a bad idea. If you're unsure of where you are in your interval, just change it anyway.
I'm actually curious as to what they tested your oil for. I work in an environmental laboratory, so I have somewhat of an idea of what you'd want/not want to see in an oil sample for this application. Is there any way you could post your results?
If you just want to see what they test for, you can find a sample report on Blackstone's website. They test for physical properties of the oil, about a dozen elements (contaminants, wear products), and optionally they will test for the remaining active additives (TBN).I'm actually curious as to what they tested your oil for. I work in an environmental laboratory, so I have somewhat of an idea of what you'd want/not want to see in an oil sample for this application. Is there any way you could post your results?
+1. When new, I called the Ford Customer service to ask about break-in and first oil change since the manual didn't say much. She pretty much said that the factory doesn't use a special break in fill and that I should change the oil when the car tells me to. It was on target for a very long interval and I couldn't bring myself to push that far on the first change so I changed it early.In any vehicle that has an oil life meter, I go by that. In my experience this is about a 5500-6000 mi interval.
One concern I have using the "intelligent Oil Life Meter" is the fact that it's configured based on the manufacturers quest to publish the lowest annual operating and maintenance figures in the highly competitive market, so obviously its taking it close to the limits of most lubricants.In any vehicle that has an oil life meter, I go by that. In my experience this is about a 5500-6000 mi interval. Local transmission shop recommends a flush every 30k miles.
I was also concerned about the long interval, so I have tested every oil change except the first one. The second one I tested at multiple mileage intervals to see and establish a baseline and to approach the service limit without going over.... so obviously its taking it close to the limits of most lubricants...
You are absolutely correct. Changing at 5,000 miles is well within the safety zone and you probably don't need oil analysis with regard to remaining service life of the oil.... to do my oil changes at around 5K miles, which it long before one expects any degradation of the oil, and this makes it pointless for me to get lab samples.