We usually head east from San Diego when we take off on an RV trip. I haven't filled up with California diesel fuel in almost a year. Our 150 gallon tank makes it easy to get to Yuma (3 hours) or some other Arizona town, so that's where I've been fueling up. I filled up in Yuma three days ago, and after driving back to San Diego, I'm only down a little more than an eighth of a tank.
I filled up the Jeep while we were visiting Tombstone last week, and gas was $2.14 per gallon. That's more than a dollar a gallon cheaper than at the 711 near my house.
Kev