I found this on another board. I don't agree with everything but for the most part, it's correct.
Lets look at the Diesel proposition and I think you'll understand why Ford dropped it. First, I don't think it would ever get 25 MPG in a 1/2 ton, unless it was a 4 cyl 180 Horsepower Diesel, and although that would do the job fine, Americans wouldn't accept that. So the engine would likely be a 300 Horsepower 400 torque V6 Diesel that got the same economy as Ecoboost.
But just for arguement, lets say they did magically get 25 MPG highway. You own one for 80,000 miles.
80,000/ 25 mpg = 3200 gallon, times 3.331 per gallon (national average) = $10,659.20 in fuel
Compared to Ecoboost at 21 MPG
80,000/ 21 MPG = 3809.5 gallons times 3.07per gallon = $11,695.17
So the "magic 25 MPG" diesel would save you $1,035.97 in fuel. Now lets look deeper. For my speculation Oil, the capacity of the diesel will be much larger (oil change intervol will be simmilar based on 6.7L Power Stroke vs EcoBoost intervols). So lets say its 7,000 mile oil changes. EcoBoost takes 6 quarts of oil vs lets say 12 for the Diesel (most 3/4 tons take 15-17, so lets say 12 to be slighly less since its a V6). So in 10 Oil changes you'd be buying 60 more quarts, O'Reilly has store brand oil on special for $2.99 per quart so you're talking another $179.40 in oil.
Also the Ecoboost takes a Fl-500S OIl filter (O'Reily lists it for $7.99), a new Power Stroke takes a Fl-2051 (O'Reily $23.99) so now the Diesel adds another $160 in oil filter costs.
This drops our savings to $696.57 (1,035.97 -179.40 -$160)
Now lets look at Fuel Filters. Lets assume the diesel requires one every other oil change like the Power Stroke does. A FD-46.15 sells for 62.99 (again Oreilly), so now we've got another $$314.95 in added expense for the Diesel. This drags our savings down to $381.62. For some you can stop here, but for those of us in the north we have an additional factor. Cold weather. Blended diesel fuel will drop that economy drastically, and we also have to add fuel additive to prevent gelling, this will easily shoot the $381.62 in fuel savings. Also if this engine is to get economy and meet emmisions it will likely have DEF injection (look at economy gains of 2010 Ford or GM engines compared to 2011 due to urea)
Now lets assume that you didn't have to buy any additive and stayed where fuel didn't get blended so you saved the $400, do you really think you'll be able to buy the Diesel option for $400 more than an EcoBoost. Considering a 3/4 ton Diesel is $7800 over a 6.2L, even if you 1/2 that, its safe to say the Diesl would be $3900 (and I seriously doubt that would cover it with the cost of DPF system and Urea injection, I'd bet on $5000 or more).
Now tell me how a Diesel 1/2 ton will save me money?
http://www.eia.doe.gov/oog/info/gdu/gasdiesel.asp Also- on resale
I also predict (but admitedly this is educated guess) that this will be getting worse. We're seeing used diesels getting harder and harder to sell and banks are no longer eager to finance high mileage diesels. The high cost of repairs is making it much harder to sell older trucks than it was a few years ago. I don't care what brand of truck, the repairs on a Diesel cost exponentially more than the same repair on a gas engine. This is hurting the high mileage stuff now, but it will start a trickle down effect