I found out the difference between 10-40 dino and M1 5-20 with cold temp starts in Maine in 1978. The lifters in my Chevy V8 clacked loudly with the 10-40(not to mention the longer crank time), but after changing to 5-20 M1 no lifter noise at all. Also the starting time at -20F was much faster. Made a believer out of me. Thanks for the video.