That's a real good link, but somewhat old, Scott suggested using 5W30 with the 3V's also but that opinion has changed since then due the to VVT! (He did say that he didn't personally do tests on the 3V though)Oil ? for modular powered Mustang owners - Corner-Carvers Forums
There's the original discussion on CC. I've been running 5w30 since I read it. Haven't noticed a difference in gas mileage. It sucked with 5w20, and it still sucks just as much with 5w30.