Pretty similar to my experience... 5.7/6sp/3.55's in a single cab 4x4 with very heavy 32" mud tires. After putting a camper shell on my highway mpg went up and my city went down.. I guess to be expected.
My last tank hand calculated on 583 kms was just over 30 mpg US gallon, with a 70/30 mix of city and highway with hilly roads and lots of slow downs for small towns. Love my ECO. Crew Cab with 6'4" box and 3.55 gears.