Unless it's a lot different from STP (which I doubt) it would be hard to persuade me to do that.
Jerry
There’s a “project farm” video where he compares New STP, Old STP, and modern 5w-30 in several tests. Both the old and new STP had shockingly low levels of zinc, even just compared to the 5w-30.
Wonder if that aspect contributed to your failures with STP?
