Check out the link that Devon posted, it's well worth the read. Modern oils, even synthetics, just don't cut it anymore. I've also read that the current spec is loading even more calcium in and the end result is the ZDDP is getting washed off prermaturely. So now I'm thinking of doing more frequent oil changes with low or no detergent oils and ZDDP, - essentially the same stuff that was used back in the day. Sorry to hijack the thread...but ZDDP is important to old flat-tappet motors. As for the 68 Sportwagon; - nice unit! I used to have one, and I enjoyed the car a lot, but the wife hated it and forced me to get rid of it. Kinda wish I'd have kept it now...
Apollo to Houston, some synthetics need the same additive for the same reasons as the other oils sold these days. Find some specs on your oil's percentage or parts-per-million (ppm) of zinc and phosphorus so you know what you have, or don't have as the case may be. The high pressure ingredients don't do the job alone. Devon
