Well said, Wha Who. The people who claim the most expertise on synthetic oils almost always admit they have never used it. I am going to copy and paste a posting I just made the other day on Old Wrench on this topic. Let me know if pasting a posting I made myself elsewhere has some sort of Netiquette rules, but if I thought so, I wouldn’t do it. And, yes, I am well aware there will be someone who says labs don’t know what they are doing, hee, hee.
On automobile forums, people are all over the place on when to change oil, with personal preferences being a major factor in the decision. However, too many people push their personal preferences as if they were on a stone tablet carried down from the mountain top, which can be really confusing when there are different personal preferences. Not to mention unpleasant at times when someone tries to force his opinion on others.
The most common personal preference seems to be oil and filter change every 3,000 miles. I have no problem with this decision, even if it could be shown to be unnecessary. Thirty dollars, 30 times, in 100,000 miles is peanuts compared to cost of a car or new motor. If someone feels better doing that, they sure need not explain to anyone. In fact, if a person has no specific reason when to change oil, but believes it need to be done more than factory recommendation, I think 3,000 miles for average drivers with traditional oil is probably a good idea.
Some people have reported similar cars in Europe have very long factory recommendations on oil change numbers, but no one seems to know why, unless it is a desire to reduce waste oil.
I am not exactly an average driver. I sometimes leave McAllen and drive thousands of miles before returning, and do not feel compelled to stop on the highway to change my oil at 3,000 miles as I would have in 1965. Oh, wait a minute, it would have been every 1,000 back then, right?
Also, over the years there have been some strong, but at times also wild, opinions stated on oil. One of the wildest was a person in the last week or two on CT who suggested anyone who believed synthetic oil had any advantages was experiencing the placebo effect. Blechhh!!!
So, finally, earlier this year, I decided to run my oil a bit longer than usual and have it tested to settle the matter once and for all FOR MY DRIVING PATTERNS. I didn’t realize at the time all the information one gets in the test. I thought I would just find out if the oil was still usable. (It was.)
My driving, mileage wise, is mostly highway, but I spend some months a year here in Mexico, in a dusty quarry town, and take a number of short trips a week, plus several hours to the city for shopping each month.
I returned to the States in early October, and changed out my Mobil-1 EP, and Toyota filter, which had 8800 miles on them, and the motor had around 158,000 on it. I sent a sample to Blackstones. I do not intend to endorse them over any other lab, assuming others exist. It was simply the one I read about. I think by the time I paid (Fed Ex or UPS? I forget, though I know where the drop-off place is) shipping, to avoid dealing with government employees, it came to the thirties.
I expected to post the report but it says Copyright all over it. I can see that. If I start summarizing or explaining it, I may not do it accurately.
To my surprise the oil test is a good report on engine condition and wear. They check a variety of “wear contaminations”, compares them to their running average of test customers, and explains what that contamination tells you about your motor. If your lead contamination is high, that implies, for example, more bearing wear. There is one which they say may indicate worn rings with blow-by. Copper might be wear on another part of the motor. There are others as well. Water in the oil is measured. Gasoline. Antifreeze contamination will be reported. Silicon indicates the amount of dust which gets past the air filter, and mine agreed with use in a dusty quarry town, heh, heh.
The average mileage on a Blackstone oil test is around 4800 miles, as compared to my 8800 miles. Some of my wear contaminations were higher than average, but not in proportion to the fact it had nearly twice the miles on it.
The ‘tbn’ whatever that is, which they say correlates to remaining additives, was around 2, and new runs perhaps 10 or so. So, at 8800 miles, I feel (my own ignorant opinion, or personal preference if you wish) I would not want to have used that oil more than 10,000 miles or so.
Blackstone did not exactly say the oil was still good. What they said was they recommended testing it again after another 7,000 miles. I may be wrong, but I cannot imagine their lawyers telling them to recommend putting another 7,000 miles on bad oil.
At the same time, I also don’t feel compelled to change my Mobil-1 EP oil under current warm weather driving conditions before perhaps 7,500 miles minimum.
I had thought to do this testing only once. But, now that I have learned it supplies a lot of information on motor condition, I will probably do it every year or two. It’s just too much information for too small a price.
I am not going to ‘recommend’ others have their oil tested. I will say that the information it supplies on the condition of the motor makes it a rational act if someone wants to do it. The thing to remember is each car and its maintenance and its uses are different, so one cannot use my test results to make his own decision on oil changes.