It's hard to find much info. This is the first time I've seen any BSFC numbers (outside of a few comments posted elsewhere).
But the '03 chart on the CTD
pretty closely follows my experience for under 60 mph (24-26 mpg, empty or loaded). I don't think 24 at 70 is do-able due to aero resistance.
Original article is a decent read, but without links to other articles cited, not worth much in and of itself.