I think giving the diesel option might be interesting, those that have been around diesels know they come with inherent problems. One being that initial cost, wow a huge jump over the other options. Also, something they don't tell you is the operational cost. Diesels are way more expensive to operate, don't let anyone kid you any different. All their parts are more expensive and normally they use much more oil and many more filters needing changed. And they are really not a mom car to go short distances for daily driving. Diesels need heated up before being shut down. Wet cool stops don't help gas engines either, but they can take it a little better.
Diesels need worked, so for rigs pulling or hauling, a great choice. Everyday short town runs, not so much.
And with new emission regulations have killed the mileage the diesels once had over the gas counterparts. So for the initial cost jump, maintenance costs and fuel costs just don't pencil out for any fuel mileage savings.