They are both anti-wear, with moly having been around the longest (?), but cost aside, does anyone know if one is "better" at its job than the other? (Is it boron or borate?)
I don't know. Redline seems to prefer moly. There are many ways to make a good oil with different components and additives. Why do you ask? Both are used for different purposes too.
Boron can be a part of additives that perform several different functions. It's not correct to say it's only for anti-wear. All you see of it in a UOA is boron element concentration. We can't say what it's purpose is because we'd need to know what molecules it is part of.
If you read enough patents mentioning boron-containing crankcase additives and read R.T. Vanderbilt's literature on their boron-containing additives, you will see what I mean.
Here is some information I posted a little while back. I read a study explaining the different AW/EP agents and it seems the Boron compounds are much more effective because of their physico-molecular properties while operatin under conditions found in engines. They also form "frictionless" plates similar to graphite that are bonded to metal surfaces. More 'high-tech' chemisty than Moly but can be expensive depending on the form it takes. Mostly seen high numbers in MC 5w20 and Penn YB. Maybe that's why they perform so well.
Originally Posted By: JohnBrowning
Well when have seen more then 150PPM of Boron in anything? If ever we say a lot of it in something maybe we could get a better handle on it!