...I was towing an ox cart heaped high with elf carcasses. WOW, what a power loss! Water temp was up, and power was down. But I just had to try it. I took a slower speed 200mi trip with the GC, then drained 5 of the 6 quarts of GC out when I returned. I added 5qts of MC 5W-20 and took the car for a spin. It felt like the engine was on nitrous compared to it having a belly full of GC. But don't worry. The GC is resting safely in a Wal-jug. The good news is that I really liked the smoothness of the engine with the GC. I have since gone to PP in the crankcase, and it behaves much like a thinner GC so far. Use it. Thanks to the forum for bringing both GC and PP to my attention. They are exactly what I am looking for in a street motor oil. I will try GC in both the LT1 and 351W next time, and all of the 4-stroke lawn equipment engines!