I am bit late to this thread...but I am also looking to buy a pick up truck this year and interested in fuel consumption. Because of my "lifestyle" these days, I get to rent a new car almost every week. These are just my own personal impression, so take it with a grain of salt..
Last week my rental was a basic 2018 Ford F-150 4x4 XL with a 3.5 V6 (not eco-boost). The mpg was at 19mpg when I picked it at the SFO airport and I got about 18.5 hand calculated mixed driving. I was not impressed with the handling, steering felt "loose" - given it was a rental, but that's the second one I rent and they both had the same issue (the other one was 2wd). Maybe just a bad coincidence, but it did not feel that different than the old beat up 2001 Ford Expedition we used to have... They are the best selling vehicle after all, so they must be good vehicles though. I am hoping to try one soon with the Eco-Boost and better options,
This week for my rental in Houston I have a new Ram 1500 "LoneStar" edition with the 5.7 Hemi and about 3000 miles on it. The power and driving is awesome. When I got it the average mpg showed 15.4. I reset it and I am about 16.5 right now. I love the truck but I am quite disappointed about this - my father has a 2015 Ram 1500 with the Hemi and it seems like the mpg is about the same, despite all the "improvements" Ram has added in their new truck. I still have it for a few days and I will report back when I am done, but if the average really stays around 16 mpg, then I would think you're even better to go with the 2500/3500.
Oh and before that, I also rented (twice) a brand new Tacoma. Damn I am not impressed with the automatic transmission and the way it shifts. It feels like it's always searching for the right gear. I think Toyota really dropped the ball with this engine/transmission combo. Anyway, I got about 18mpg each time. Again mixed driving,
And since we're on the topic, I also had a brand new Jeep Wrangler 4-doors 100% stock a couple weeks ago and barely averaged 18mpg. No doubt the new Jeep is better overall, but I was also a bit disappointed by that. I can't imagine what it will be once you add larger tires and a roof top tent...
When I am home (rarely...), I drive an old 175000 miles 2003 BMW 4.4L Sport that has 300Hp and gets about 17mpg...still one of the best handling cars I have driven in my life.
I think they only way to get anything with a significant mpg increase would be to go diesel - either the Chevy Canyon diesel or the Ram EcoDiesel.
Or perhaps the new Ranger with the EcoBoost. They look very nice in person, I can't wait to try one.
The quest continues...