[ademonrower]

WOW! I am impressed! Thank you very much for those extremely helpful and generous suggestions! Will look into them soonest. I had, indeed, heard of boron-compound additives. They seem to be better at reducing friction and wear than molybdenum-based ones, but I hadn't yet found such a detailed analysis as the one you sent: much appreciated! I understand that it's a tricky business adding things to oil, because some of them might react with the additives already in modern oils. However, it appears that the boron compounds are very inert and temperature-resistant. I had up to now been adding an organic zinc compound to my oil. These were dropped as soon as cars had catalytic converters, because the tiny amounts of zinc compounds in the exhaust gas could, over many 1000s miles poison the catalyst. My car doesn't have a catalytic converter (the US was miles ahead of Europe in that respect! Shame on us :-)