You're not going to find this as reliable information because I'm not an ASE certified oil changer, but it's a hobby of mine. My only hobby. I've built more engines than I can count, and do engine swaps when I feel like it. My current car is a Fiero with a 3.4 DOHC turbo making 487hp on the stock block. I'll give you details, but this isn't your ordinary Fiero.
Oil temperature is the most crucial thing to longevity there is. Used Wal Mart brand 5w30 protects better at operating temp than any cold synthetic out there.
In that case, I'd honestly take the highway still. What car do you have that doesn't have an OD gear? My aforementioned Fiero even has OD!