RLI 10w30HD is loaded with copper
"This is the point at which RLI began to develop alternatives suitable for vegetable oils and turned to soluble copper compounds. They discovered that several types of copper compound could be used including copper dihydrocarbyl thio- or dithio-phosphates, copper dithiocarboamates, copper sulphonates, carboxylates, and phenates. It was important that the additive should be oil soluble for the oxidation inhibition to be effective. By putting amounts from 50 to 3000 part per million (ppm) in the oil a remarkable effect was noted."
"RLI then discovered that by reducing the copper level to around 500 ppm and adding 500 ppm using a second antimony oil soluble compound, wear was brought down below that seen with sunflower oil alone. Now with only 500 ppm copper and 500 ppm antimony the oil is not only oxidation resistant, but also wear inhibiting."
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RLI Article