This is a thread about engine oil, there's no room for proof or evidence here.
:rofl:
Seriously though, I don't know about zinc (ZDDP) costing power, we're talking about 800 ppm probably being too low for a flat tappet engine and 2200 ppm probably being too high to run consistently. That's parts per MILLION. A 1400 difference in parts per million is not a huge difference to the overall composition of the oil when those parts are microscopic. From a wear package perspective it's a huge difference, but I don't see how an engine is going to lose measurable horsepower from that.
