The math doesn't add up jack ass. You are basically in the realm of 200k miles to see the cost savings on ah the money you just spent to be "efficent".
This is diesel bros new argument btw. That the truck gets better mpg there for it's better for the be environment.
My dad was one of the guys op is talking about and used to drive me to school in his truck about the time my ibs started to become a thing for me. That smell is extremely strongly tied to memories of feeling like absolute dogshit every morning all through 6th grade. Fucking hate it