I have recently become aware that current motor oils are profoundly lacking enough zinc phosphate to adequately lubricate older engines. Manufacturers are reformulating oils for modern cars at the expense of much needed additives. It seems certain of these additives damage Catylitic converters and the laws are restricting them. This is not snake oil talk it is very real. It is especially important for pre war cars, any flat lifter/cam motor, and installation of new cam/lifters for break in.
Two of my British Car customers have had a major failure with new Cams. I now learn that lack of sufficient zinc (ZDDP) in the oil is probably a supporting if not causation of the problem.
I now am now on board with what looks to be the best solution on the market...."ZDDplus". Anyway I wanted to offer the group an opportunity to purchase a small quantity (5 4oz bottles) at a 25% discount to the retail price of $9.95/bottle. That would be enough to do 5 oil changes. A brief run down of the problem:
Other informative links:
Scroll down about one third of the page and look for:. Zinc Dialkyldithiophosphate
Feel free to explore this excellant site.
Valvoline responds regarding a Jeep motor.
A little preachy and biased to synthetic oil.
More information about the product I sell at: