Summit Racing oil

The people that designed these engines decided straight weight 30 was good. Then guys started racing ...higher oil temperatures...now let's say they lived in a cold area / region like Michigan or Detroit to boot.... so they used 20w 50.
All I can say is I would only go lower in much colder temperatures and for no other reason otherwise. I would go heavier due to extreme temperatures from high rpm operations or higher ambient temperatures and no other reason otherwise...Lmao..:rolleyes:
No one should need to tell you what oil to use be a big boy do your homework ...and use common sense that can rebound off history.