Could anyone tell me how many MPG this rig should get (aprox). It is a 4 cyl. 4 speed long bed YELLOW and well rust

BUT his earned the $$ himself and he is very proud as he should be. It runs great!!! Reminds me of the good old days The days of the 2-50 AC (2 windows down and 50 MPH) also how many gallons of gas does it hold. (I need to know how far away he can go)