I have also been awaiting the release of a diesel in both the Tundra (more specifically I want a diesel 200 series Landcruiser) as well as the F-150. Realistically a F-350 makes more sense for what I plan on doing eventually, but in the interim, I could get by with a F-150 diesel for a few years. However, when I compare a 6.7 F-350 to a 3.0 F-150 on purely the cost difference in fuel expense, it's just not that big of a difference to justify the less capable F-150. Figuring 15,000 miles a year, and 18 mpg vs. 30 mpg for the two vehicles, the F-350 would burn 333 more gallons per year. At $3.50 a gallon, that works out to $1166 a year or roughly $100 more a month to drive the bigger, heavier (safer) and more capable F-350. Unfortunately, at least for me, it just would not make sense to buy a diesel F-150.
Also, with the excellent performance and broad torque curve of the Eco-boost, I'd have to give the nod to that engine if I was going to buy a F-150. It's a great performer.
However, I think these engines will sell well, perhaps very well. Since most people are really bad at math, they will focus on the 30 mpg and not look at the actual cost difference between the Ecoboost and diesel options. The Ecoboost is less expensive and an extremely capable and suitable engine for anything a F-150 is spec'd to do. While there may be some breakeven point to justify a F-150 diesel, unfortunately it is many thousands of miles down the road.
