My personal take on this whole thing.... I did not read the articles you posted yet to bias my opinion.
Honestly, I change the oil in our vehicles when I am in the mood. I use to do it ever 3000-3500 miles. Using Mobil-1 or any other synthetic oil, that can get expensive..not to mention Mobil1 has an extended version good for (whatever the jug says), something like 12,000 miles for like $2.00 more for 5 Qts.......So my thought here is, so for about $.40 per quart, you can make me an oil that is good for 3-4 times the mileage of your REGULAR...Yea Right!!!! I honestly feel that the 3000 mile thing is 1.) for good ole pennsylvania crude/refined oils not the newer synthetics. 2.) for the higher reving 4/6 cylinder motors of the 70's & possibly 80's.
For this forum, I assume we are not talking about alcohol funny cars and you don't have Garlits or Force written on the side of your vehicle. Nor do you completely rebuild it after you drive it 1,320 ft. (1/4 mile).
That all said, where do you drive your vehicle, how hard do you drive your vehicle, what environmental contaminations is it subjected to? Example: I had a 4X4 Chevy PU that I drove off road quite a bit and ran it fairly hard in the sandbox type sand found in the Outer Banks of N.C. You guessed it, I switched to synthetic lubricants all through the truck, Grease, Motor, Transmission (manual 5 speed), transfer case and Differential and running in dirt, sand, saltwater etc. I changed all of it after each trip (each trip was usually 1-2 weeks, 2-3 times per year). Gotta love OBX.. :cheers:
I currently change our vehicles oil somewhere between 6-8000 miles using the mobil1 (sometimes regular, sometimes extended, sometimes high mileage..(That is a whole different ball of wax) :rofl: :rofl: Oh yea, that one has special additives to keep the rubber seals in good shape...Oh, so the regular blend is not so good for my oil seals????? Cummon!!!
Bottom line (fer me anyway) watch yer oil, you know how and where it is driven and under what conditions. Mind the mileage, but when it is dirty, change it......BTW run it all through a good filter and it is probably good for much longer than anyone, manufacturer (oil & Auto) our ourselves are willing to admit...Good Lord, when I was youger OK :nono: a lot younger it was good ole regular OIL and ya changed it ever 12,000 miles (agreed it was really nasty, BUT we had STP and Slick 50 to add to the oil.
Bob :blahblah: :soapbox: :cheers: