Why oh why do you have to bring this subject up again. Just use what ever YOU like as you will get answers from one end of the spectrum to the next. Just make sure you use one with adequate zinc, actually it is the phosphate or phosphorous, (the P part of ZDDP) is what you are after. The zinc portion, which is what they were originally after, was for corrosion protection, when it was discovered the P portion was a very effective extreme pressure additive. However too much is not good either. I can't remember exactly what the minimum number is, but there is an article by Bob Olree, a lubrication type engineer from GM who explains it very well. And just in case you are wondering who he is, I have read several other articles that reference HIS article and state that he is virtually without peer in this field. You might do well to look it up, its easy to find, since this is a burning topic with vintage engine people, and is actually on this forum somewhere. Where you will also find people with absolutely no qualfications in this field disputing the expert. So anyway good luck.
Last edited by brokenhead; 06/11/2012 12:12 PM.
