The 4 cylinder eco cars are a joke. Back in the 90's they did ok. Not so much anymore. My 500 hp Challenger makes 25 mpg. Compare that to a 150 hp Eco jap car making 30ish.
I moved to Wyoming about the same time that the Toyota Prius first hit the market. I had a friend back in Mn that I bought a car from, so I rented a car to get me back there to pick up my 'new' car.
When I got to the rental place, the guy tried (and succeeded) in upselling me to the Prius because at that time Toyota was claiming 70 mpg.
"It'll pay for the extra cost of the rental" he said.
**** thing was lucky to get 30 mpg.
I got back to Mn, picked up my $100 Ford Escort, and drove back.
And got 40 mpg.
As for pickups, my 93 GMC K2500 with a 6.5 diesel regularly gets 18+ mpg. I know a lot of older Cummins do better than that. Pretty decent for heavy duty pickups, IMO.
Good luck in your search!