JohnKSa, what you seem to have gotten from Grant Cunningham's article is that motor oil is no good as a gun lube.
I wasn't trying to interpret it. I don't think it needs any interpretation--it stands on its own.
What did I "get" from the article? I've made three statements about motor oils based on or at least supported by the article.
1. Motor oil pour point additives can be toxic.
2. The corrosion protection offered by motor oils is inferior to what is available from the best gun oils.
3. There are better choices than motor oil for a gun lube if one chooses not to use a gun specific product.
Here are Grant Cunningham's statements from the article:
1. <motor oil> "pour-point additives often contain benzene compounds, which aren't a good thing to have next to your skin on a regular basis!"
2. <motor oil has> "...very poor corrosion resistance..."
3. "If you must use something from the auto parts store, ATF performs better <than motor oil> for firearms use on every count" ... "What do I consider a "best in class" oil? Generally, it would be one made for lubricating food processing machiner, like Lubriplate's FMO-AW oil (specifically the 350-AW weight.)"
I don't believe I've misrepresented his opinion/statements as aired in the article (or in his revolver book which contains a section on lubricants).
I interpreted it to support the hypothesis that motor oils are excellent gun oils.
(My emphasis added.) I don't see how one could draw that conclusion from the article.
Here's a section you quoted from the article with some different emphasis added. We'll take it as a given that your comment about synthetics being resistant to open-air oxidation is accurate and not emphasize that portion.
"Motor oils: Generally good boundary lubrication (particularly the Havoline formulations), but very poor corrosion resistance and poor resistance to open-air oxidation. In addition, their pour-point additives often contain benzene compounds, which aren't a good thing to have next to your skin on a regular basis! If you must use something from the auto parts store, ATF performs better for firearms use on every count, even if it is a tad more expensive. (ATF is still 1/10 to 1/100th the cost of a specialty "gun oil.”) "
He does state that motor oils provide "good...lubrication" but every other comment in the paragraph is negative. And he then makes the further statement that if you want to use an automotive lubrication product, ATF is better than motor oil "on every count". I don't believe that comes close to saying that motor oils are "excellent" gun oils.
I guess if one were to interpret his comments as being an endorsement of motor oils as "excellent" gun oils" (ignoring that he scores them as "good" in one category, "not good" in another and "very poor" in a third) then one would have to assume that ATF is
better than excellent "on every count" and that Lubriplate's FMO 350-AW is even
better than better than excellent.
The close of this paragraph is almost a flip-flop, because what he wrote earlier in the article about ATF didn't seem nearly as supportive:
The paragraph before the one you quoted was actually quite supportive:
"...there is one product that does pretty well in corrosion resistance (not great, but better than average.) It also has good migration, a fair boundary lubrication package, is the right weight (thickness) for general firearms use, doesn't oxidize over long periods of storage, and is compatible with a wide range of metals and plastics. In addition, it is recommended by at least one real degreed firearms engineer! Just what is this miracle elixir??
...
Dexron-type Automatic Transmission Fluid (ATF). ..."
I believe the article makes it plain that if he were to pick an automotive product for use on guns, it would clearly be ATF, not motor oil.
Would it still be alright then, if I use Mobil one on my stainless steel 1911 Colt Commander then? Or, is there some ominous reason not to?
Obviously it's alright for you to do anything you want with
your pistol. And, just as obviously, if you aren't concerned with corrosion protection then there's no need to be concerned with corrosion protection.
I'll use something else to lightly coat other parts of the firearm which need rust protection; usually Breakfree CLP or Eezox (but my wife hates the Eezox odor, even if it's opened in the garage).
Beeman MP5 is, in my experience, an excellent rust preventive. However, it is not a lubrication product in my opinion, and I wouldn't use it for anything other than rust prevention. But it has a very mild odor and if you're just looking for a product to use to wipe down parts that need corrosion protection it's a good choice.