That's open for discussion. Gas is $3.79 and diesel is $4.65 here. The 6.4 diesel has had some issues and does not get very good fuel mileage. The gas 6.8 V-10 is solid and proven. The only thing I would NOT get a SD with is a 5.4.

 

I traded in my 6.8 superduty a couple years ago for a 5.4 F-150, the 6.8 and a sts turbo would be cheaper than a diesel and would pull great...

 

Seems to me a stock 6.8 pulls just about anything within the rated limits of the truck reasonably well. It will pull its limit as well as a 150 with a 5.4 will pull its limit. Diesels obviously should have higher limits.