MG McAnick; I remember that test and it was done by Cosumer Reports. The only problem with it was that taxis have very few cold starts per 10,000 miles. They essentially run all day, and that kind of driving is easy in the engine. New York also has a mild climate compared to Minnesota or Montana.
For the average US driver this test was meaningless and dangerous if a driver arbitrarily went to such a lenghty interval while, say, being retired and living in the Northern US, driving only 10,000 miles a year, and parking outside at night.
I posted the blog link strictly for information. I do know a couple years ago, I let my Mobil-1 go 8800 miles of highway driving, strictly to find out if y’all really know what you are talking about. (Some of you do, the 3,000 mile advocates do not; the ones who say synthetic needs the same change cycle also do not.) I had it tested at Blackstone, and at 8800 miles all parameters, repeat, all parameters, were good for at least 10,000 miles. Contamination; additives; everything.
I would not want to try to run it more than 10,000, and this was highway driving in warm weather outside the snow belt.
Anyone who says you need to change your oil every 3,000 miles no matter what the driving conditions are, is filled with pure nonsense, and I don’t care how big a shot he is. Enough already. You want to change your oil every 500 miles, that is your right, but when someone tries to push 3,000 mile changes for everyone, that is pure and utter nonsense.
I personally prefer 5,000 miles max, no matter what kind of oil you use, because I believe that synthetic is as subject to dilution and contamination as dino is…and because engine replacements are downright expensive. I support those who prefer 3,000 niles because if it helps them sleep better, why not?
I do not subscribe to the theory that synthetic can go 10,000 miles (or more) between changes without any risk. It may be completely true, but there just is notany data out there that I’ve been able to find showing causal relationships between the type of oil and engine wear, longevity, or reliability except those published by the perveyers of the product, and I never believe their “studies”. Besides, I think the only “studies” I’ve seen from them are lab results and not actual data.
I’ve always used dino, change it at least as often as the manufacturer recommends, and never worn out an engine. I was discussing this subject with my neighbor recently and he made a good point, however. He said “yeah, but every time I see you you’re working on your car. You’re always changing the oil, examining the filters, or something or other”. He’s right. I just might be the amount of maintenance I do. I was standing there with a spark pllug in my hand as we were speaking. They looked beautiful. Changed 'em anyway.