... sit tight for a story...
So a few years ago, I was at a parts store and they had a little diagram of gears, sitting in oil. One set had normal oil, the other had lucas additive. The normal oil did not flow and coat the gears as they turned, and the lucas oil did. So I thought "this is cool" and I started using Lucus additive in my motor oil. The whole idea behind Lucas additive is to stablize the molecular bonds in the oil, so it flows at an even viscosity, doesn't tear under heat, and pro-longs life and performance of friction parts.
A couple years later, my brother started noticing frothey oil residue on his filler cap. So he did some investigating and research on the Lucas additive. He found a web article where an engineer did some private testing of the lucas additive. He made his own test transmission and ran lucas at appropriate rpms in the test.
His test revealed, that over a short time, at realistic drivetrain rpms, the lucas additive actually turns the oil into a frothey lather, like hand soup. Yes the additive improves molecular bonds, but it turns the oil thicker, and inturn creates a wipped cream type effect.
... so basically, you're engine is left running on airbubbles of oil.
Now, I searched again and could not come accross this article. And I cannot recall if this guy performed the tests at realistic driveline temperatures. But since seeing this, I have stopped using Lucas additives... just to be safe.
I am already using Ams Oil synthetic motor oil, and I take care of all the fluids. Most high end oils already have lots of goodies to help your driveline run healthy, so I figure I'm okay without Lucas.
now that said, Lucas is heavily used in the NHRA and motor sports industry, so I could just be full of sh*t... But just thought I'd throw it out there.
If I find the link again, I will post it here.
