I figured I would reply to this thread, rather than make a new one. I recently saw this video, and was intrigued about the premise of the test.
They mention the test ran for 4 years, and a million miles. People here are questioning whether the test was valid, because the engine was running highway miles and was generally warmed up the whole time.
However, if you put the math together (failing to take into account the 50K durability test done in the beginning)...
1,000,000 / 4 = 250K annually
250,000 / 365 = 684 miles daily,
Which, if you /24 to get an hourly average = about 29 mph.
Mobil's video states the vehicle was running between 45 and 85mph during their extended test. These figures suggest the car was only running around half the time the test took... Could this suggest a daily cold-start? Or downtime?
It would have been really great if Mobil had used two of these vehicles, one with the Dino of the time, and one with the synthetic product in the video. Then run on the same intervals with the same maintenance, etc. Then tear down at 1,000,000 and see what sort of difference in wear is, to prove whether synthetic was really 'worth it,' or not.
They could also have run the engines till failure, too