BTW if I get 20MPG I will be dancing in the streets. MY old rig, a 06 chevy duramax got 12 in town and 16 on the hwy.
I've checked mine twice in the past couple weeks. One tank full I had probably 300 miles, 240-hwy and 60-MUD4x4 at fill up I got 19mpg. Today I was 270 miles, 200-hwy and 50-around town, 13.10 gallons so right at 20mpg+
I have 13,500 miles on it. 2011 4x4 LB.