Found this, could be BS but I doubt it. Too many details that are known accurate or sensible:
Quote:
I am an engineer with one of largest manufacturers of engines in the world, a company that sells billions of dollars of them every year. Items #1 and #2 are terribly incorrect.
EVERY engine that we manufacture goes from assembly into a test cell where it is started, warmed up, and sent immediately to 100% full load. Yes, it is "floored."
When we do engine testing, even prototype engines are assembled (mostly with Lubriplate 105), warmed up with standard petroleum oil, and immediately go to full rated horsepower while the dyno pulls them down from rated HP to the lowest RPM of torque peak.
Almost every automotive manufacturer follows this practice as well. So do motorcycle manufacturers. I personally saw new Ducatis going off the line in Bologna into a chassis dyno where they were started, briefly warmed, and then immediate run up AT FULL LOAD all the way to redline.
Why do they do this?
1) The freshly honed/machined surfaces can only do an ideal break-in when they are, in fact, fresh. Once the asperities and surfaces begin to smooth, they lose the ability to mate to each other properly.
2) It prevents customer complaints of high oil consumption and poor MPG because customers tend to follow outdated, bad advice like babying a new engine.
Back when machining and honing technology was far less advanced, and tolerances could not be held as well, there was perhaps some validity to babying a new engine. But this advice is woefully out of date.
Instead, the best thing you can for a new engine is:
1) Warm it up to full operating temperature
2) Do several full throttle runs that stop well short of redline
3) Idle the engine to let it cool a bit
4) Repeat steps 2&3 several times
5) Change the oil and filter.
Done.
By and large, new engines require almost no break in at all because of the "abuse" they suffer at the factory. That's why they can ship new cars like Corvettes with Mobil 1 from the factory. No need to worry about the syntehtic preventing break-in when the engine is already broken in before installed in the car.
End quote.
