Gas and diesel has been see-sawing with each other for many months here in on the West Michigan Lakeshore where we live. Lowest price we've seen for gas was $2.57 and diesel was $2.61. Both were in the $2.80's this morning. Seems the price changes everyday either up or down a few cents.
When the price of each is the same, Diesel has a big advantage in cost/mile of driving as diesel has 12% more energy in it per gallon etc and that alone with the diesel price at $2.80/gal equates to the price of gas needing to be $3.14/galt o drive the same distance (miles) with both comparable vehicles.
Then the fact that a diesel engine runs at a much lower RPM's than a comparable size gas engine, we experience an honest roughly 30% to 35% less fuel consumed in our diesel engine vs our gas engine truck. Especially when towing or hauling heavy. Had the very same heavy Lance truck camper on both our gas truck and our diesel truck and we seen the difference constantly on the many trips driven. Until last year when we finally stopped keeping a log book, The diesel truck consistently got between 1.36 to 1.55 higher MPG than the gas trucks whether towing our 5th wheel or with the Lance on over a total of more than 470,000 miles driven with the trucks.
A superb CC LB 4X4, GM HD Diesel, airbags, Rancho's, lots more
Lance Legend TC 11' 4", loaded including 3400 PP generator and my deluxe 2' X 7' rear porch
29 ft Carriage Carri-lite 5'er - a specially built gem
A like new '07 Sunline Solaris 26' TT