The old Filtrate Colloidal Graphite did the same job, I still have the remains of a gallon can of it. It worked well in the 1950s oils. It was good stuff.
I used to tip a can of STP into the oil tank of my old Triumphs when I rode them, it took up a lot of slack in my worn engines.
In the 1970s I ran a 400e Ford Thames van, I fitted Cord rings to it and ran it on a mix of 40grade oil and STP; you could not hear it ticking over, had to rev it at traffic lights to check it was still running. MInd you I had two walloping great batteries fitted in it to turn it over from cold.
rambling somewhat off the topic,but what the heck just had my last glass of rum.
