I have seen this oil mentioned here, and the Chevron website also shows it, but I've never seen it anywhere for sale; the only place I've seen Chevron is at Walmarts, but they only have the 10/30 & 10/40. Does anybody know if they carry it? or was is always sold-out, when I looked? I've also never seen any Chevron 5w/30 dino or any Chevron syn-oils... I'm not necessarily going to use this 20w/50 oil right now, BUT, in case I need a chevron-"soup" someday...20w/50 & 10w/30 for the summer...(I once dreamed about mixing these two...one of many ways this page is affecting me, I guess) I'd really like to know where to find this. Does anybody know? oh, another question: --can Chevron dino 10/30 and Delo400 15/40 be mixed? any potential problems? Thanks.