The bel air probably doesn’t have any emissions stuff. That’s why it gets better gas milage than you expect, whereas the newer stuff absolutely does. Plus trucks are geared for torque, unlike a car, which reduces mpg. A more apt comparison would be to older ('50-'70s) trucks, where you were probably talking more around 9-10mpg without emissions.
The bel air probably doesn’t have any emissions stuff. That’s why it gets better gas milage than you expect, whereas the newer stuff absolutely does. Plus trucks are geared for torque, unlike a car, which reduces mpg. A more apt comparison would be to older ('50-'70s) trucks, where you were probably talking more around 9-10mpg without emissions.