You can continuously cold start your vehicle with 5w40 at -30 below F. I'll just stand there and listen / watch
Any BITOG member here with a couple ounces of posts under their belt, already knows 5w40 is fine when the vehicle is warmed up, in a cold spell like 30 below. That's not why I differ.
Pleaase, no mentioning PAO oils that deliver great cold performances in 5w40. PAO is in very little oil brands & viscosities these days. But feel free to mention the 5w40 oil brands you cold start continuously without rattle at -30F. I'll folder them for future use / recommendations