So I went to checker and bought 5w20 conv .49 and 20w50 syn .99. 20w50 was to only syn left on the shelf that was on sale, so couldn't pass it up. My plan is run a 50/50 mix during the summer. The two are Valvoline Syn and Shell conv. My main question is will this mix offer more protection than a conventional 5w30 or 10w40 oil? Thanks.