Since we're taking about Delo, I had an interesting experience looking for it that might be of interest to the group.
I'll have to start off by saying I am a very new resident of the Phoenix area, so for those of you that live here and already know this, forgive the repeat.
I spent the better part of today calling around to all of the usual places, trying to find some 5w40 Delo 400 Synthetic. Wally..no dice. Pepboys...nope. Autozone...nope. Checkers...nada. I even ended up calling the Chevron distributor and he said it was a special order item and since nobody was asking for it, he didn't have any. He really didn't even seem interested in ordering any. Thinking I was out of luck, I ran across a reference on the Chevron website that Costco carries it.
So I called a few Costcos around Phoenix and no luck.
While using the internet, looking for other Costco's to call, I somehow ended up on the Costco Business site, where I found exactly what I was looking for...even listed the Costco item number. Turns out there is a Costco Business Center here in Phoenix and with a quick call, verified that they did in fact have it in stock. I drove over after work and picked up a couple gallon jugs.
So if you're in Phoenix and looking for synthetic Delo in 5w40, Costco has it. It was the only place I could find it.