I’ve an old ( P reg ) imported, Cyprus? Nissan D21 the model before the current Navara ( d22 ). 2.7td and it returns about 23mpg but I’m always stop starting, doing short runs and carrying a load. Its a 2×4 with optional 4×4 & high and low ratios. The 4×4 mode is fantastic. Last winter I towed both a transit van and the timberwolf chipper which it was attached to out if a water-logged field and uphill out of another field without slipping once. What I like most though is that it has a full-size double cab ( no half-cab here ) and full-size pick-up bed ( 7 foot ) ..bike and kit storage for me, sons & mates not a problem.
I also owned a Dodge double-cab pick-up with an 8′ bed. 5.2l v8 – 17mpg…but you travelled in absolute luxury…1800rpm at 70 and power on tap if needed.
…and had a ’78 Chevy C20 pick-up as a bit of a hobby. Had a transit diesel engine in it when I bought it so imported a 500bhp v8 small-block Chevy engine for it, race box,exhaust, carb etc. That was fun.
If I had a choice and done it all again for a daily driver I’d have a lpg converted Dodge. Lpg would equate to about 34mpg.