Ok OP I will give you honest numbers!
These are hand calc numbers recorded on every tank with 40K on the clock.
2011 HO LaramieLonghorn 4X4 Dually with 3:42 gears.
9.5 average West Coast towing a combined weight of 28K up and down I-5 border to border and associated highways. Average of many tanks. Note: 55mph minimum!
11.5 Just daily driving when in Palm Springs up and down Hwy 111 and a couple trips out to Desert Hot Springs. Average of many tanks
14.0 commuting 55 miles each way 55-75 mph along the way. Average of MANY tanks.
14.5 traveling from Quartzite, AZ to Phoenix on I-10 at 75+ mph.
This is reality!
I have to say I am very pleased with the towing mileage at 28K combined. The rest I really don't care because the truck was bought to tow.
Anyone telling you higher numbers are not speaking of the truth!
BTW never goes into forced regen. Fuel dilution is less than .05% per Blackstone reports. Oil is never over full when computer says to change at nearly 7,500 miles.