The lil Ram 3.0 economy diesel is a pretty successful focus on economy with guys often pulling off 30 mpg hwy. For a full size granted light duty 4WD truck its impressed me. Best looking fuelie numbers by far. No you can't tow a house up a mountain at 70 mph but many of us don't need that. Hope it returns and that Ford does in fact get their 3.0 diesel f150 off the ground in 2018.
As for an economy based HD Not until they affect corporate fuel economy numbers. Without it or something similar there is no real & strong incentive.