I'm still getting a pretty reliable hand-calced average of 18 US mpg, running unloaded bone-stock about 90% Highway, 10% Local/City driving, with highway speeds of 60-70 mph.
I also drive for mileage, as well as I can, but I can't resist blowing smoke once in a while
The average miles per engine hour is 37-44 over the last few tankfulls.
That is with a 3500 longbed 4x4, weighing in at about 7150-7200 lbs as she sits, with 27,000miles 43000km on the odometer.
2005 Chev K3500 SRW Dmax Allison Ext Long Box