Lucas Oil Stabilizer is a low cost and low quality viscosity improver, sold at huge markup. When you replace 10% to 20% or more of your motor oil with Lucas, you have that much less anti wear additives, less detergents and dispsants, and so on. Just cutting down ZDDP, friction reducers, and detergents & dispersants, is good enough to effectively destroy the bearings inside a turbo in a diesel engine. After that, the piston rings will wear out, because Lucas is a magnet for dirt, and also likes to create deposits. The rings will have so much wear that when remove them, you can use them for shawing. The rod and main bearings in a big Diesel engine will go last, because these bearings are so big. You probably will have to rebuild your engine before they let go, because of the increased blowby and decreased power, and probably because you're tired of replacing turbos because... you keep using Lucas. Some folks never learn.
In a personal vehicle with a gas engine Lucas will do some serious damage. It prevents oil from getting where it needs to be, fast enough, by clogging up passage ways that are narrow, like those inside an oil-coolant heat exchanger for example. That's why Lucas came out with a thinner version of their crud and dubbed it "Synthetic", whatever that means ... for what it really is.
But hey, if you, or anyone else wants to use Lucas, or keep using it, by all means. It's not my problem, and I won't suffer the consequences of such a bad decision, you will.
