Ndabunka; when I say real world I mean actually driving an extended distance and measuring the amount of gas you use divided by miles driven. A lot of people post just what their computer says, but I feel those computer numbers can be fudged a little. 22 mpg in a 4900lb vehicle driving 80-90mph isn't bad at all IMO.
At about .75 more per gallon I don't think there's much of a savings with diesel in my area. Besides getting 29 mpg in a diesel driving 80. I'd have to see it to believe it. The hwy mpg posted on a diesel is 26 and gas is 23. Now I get 1 mpg less than that at 80-90 so I'm betting the diesel wouldn't get but 26-27 mpg driving 80.
It's good to be bad