F150 Ecoboost vs F250 Diesel mileage

The cost difference between 87 gasoline and diesel fuel is the closest it's ever been in the last 15 years in my area with 87 around 3.12 and diesel at 3.69. Gasoline prices have risen alot the past 3 months here from 2.5 to the 3.12 it is today while diesel fuel cost has not changed at all. When 87 was 2.50 per gallon diesel was 3.69 per gallon and that is the norm for the past 15 years here. That over a dollar a gallon more for the diesel fuel could never be made up in mpg difference.