[johnsjmc]

I,ve only had 2 diesel trucks a leased 2005 F250 4x4 (which blew it,s trans at less than 20,000 mi after I got stuck in mud,the case cracked)
It never got very good mileage even empty it was about 15 mpg and quickly dropped even when only loaded with a slide in camper.
The other was a 2004 Dodge 2500 4x4. and my favourite. Although the F250 had a nicer cabin
I put about 120,000 mi on it ,with only routine maintenance.
It got much better mileage ,about 19-20 unloaded.
I once towed a 34 ft sailboat on a triple axle trailer (loaded was about 15,000 lb and needed wide load permits and a CVL). Towed across 4 states and still managed about 9 mpg.
Both have now updated versions of the diesels available then and the Dodge has the super size cab available.