I’ve been running M1 0w40 since day one in the BMW. I just saw this QS Euro 5w40 at Walmart for $22.97! I know QS makes quality oils as well. Would I be downgrading going to the “5w”? I’m actually thinking of using this in the ‘64 Falcon and ‘68 Buick as well since they have mild hydraulic flat tappet cams.