That's strange I have a 2014 Ecodiesel Tradesman.
and the why...The 2015 Ram 1500 Express and the 2015 Tradesmen models will get 29 miles per gallon on the highway when they are purchased with an optional diesel engine. That is one mile per gallon more than other Ram 1500 pickups with the same engine.
The improved fuel economy for the 2015 Ram 1500 models is possible because the Express and Tradesman versions of the 1500 are more aerodynamic than other Ram 1500 models because of a Tonneau over the bed of the truck, wheel-to-wheel side steps and the quad cab configuration.
Last year, Ram did not offer the EcoDiesel on the Tradesman and Express versions of the Ram 1500.