[spork2367]

Originally Posted by mlipmd

Is it OK that MH recommends Amsoil 10W-40 because of the ZDDP levels while that is different than GM saying Mobil1 10W-30 is what's needed? Does he know more than the engineers who designed this motor, or is that his personal opinion? Why does he say a "heavier" weight oil with higher levels of Zinc and Phosphorous is so much better than what the factory specifies? If it was so beneficially great, then why wouldn't the factory switch to this recommendation too?
There is not an equal difference between a 0W-40 and a 10W-30 vs a 10W-40 and a 10W-30. The factory picked a balance to cover the widest range of driving conditions, not the best for everyone. 0W-40 is in NO WAY offering any level of protection beyond a 10W-30 (weight wise). I run 10W-40 due to my operating parameters, but the Brad Penn 10W-30 would be fine.

All the 0W-40 designation means is that that oil is suited to a wider variety of temp extremes than a 10W-30
False. Several people in here have clarified that 0W oil was created exclusively for lower emissions and better fuel economy during the warm-up period and short driving done in small commuter cars. That?s it. Anything stated beyond that is marketing hype. It wasn?t created for ?cold weather? it was created to decrease the viscosity in ALL weather.

I expect next you'll say that compression testing is only an "estimate" of what's happening inside the cylinders.
It is only an estimate. It doesn?t account for combustion efficiency, flame propagation, hot spots, detonation, etc.

And explain how a lower weight oil (0W) decreases emissions until the engine warms up.
You have less parasitic loss while the oil is warming up and therefor are making more power with less fuel.

Air cooled aviation engines and liquid cooled automotive engines are the same thing, same requirements? That's news.
They are definitively not the same which I why I made the earlier comment about your generic Porsche reference. Nor did I say the requirements were the same. The principles of oil selection however are the same.

And you do realize that things do change over the years, right, that advances are made? What was originally recommended 32 years ago may not be as good as what's available now?
And sometimes they change for the worse. Which is why we have less zinc and phosphorus due to catalytic converters and emissions. It?s also why we have 0W oil. While oil formulations have gotten better, every change was not for the benefit of the car owner. Government regulations rarely benefit individuals.

The oil you use is just as much a personal preference as the tire pressure you want, as I said. All the modern oils perform pretty much the same and if you change them on schedule, you'll be just fine no matter your choice
Pick the wrong tire pressure and you?ll ruin tires too. If you?re putting around the block or cruising on the highway, you?re not going to kill the engine with 0W oil. It just won?t be the best choice for minimizing wear in the engine. All modern engine oils do not perform "pretty much the same."

There is a distinct difference between the opinion of a layman like yourself and the opinion of someone who deals with these things for a living. Be it Marc Haibeck, or myself. Nothing personal, just the facts.