One thing to consider is that, unlike a gasoline engine that does not use a residual supply of fuel in the tank to temper the temperature of the fuel returned from the injectors, a diesel truck needs cooler fuel in the tank to keep the temps down. Diesel fuel is used to cool the injectors and excess fuel is returned to the tank thru a fuel cooler. There are problems with hot diesel fuel, sometimes in the 200* area, that would be unmanageable without that residual supply. A very small tank reserve would not provide the temperature buffer needed to reduce fuel temps. CP3 pumps have a more difficult time with hot fuel in attaining and keeping the actual pressure following the desired pressure and that sometimes results in P0087. One question to consider is do you really need 11 gallons? And is that really what you have remaining? Our trucks are fitted with tanks of different sizes, 26, 34,50, at least for the 2008 models. I believe that I have put in 27 gallons on a very cool night in my 34 gallon tank, so I think the intended reserve is likely about 7 gallons.
Just don't want you to think you can get down to a gallon before your gauge says empty. That might work OK in cold weather, not so much in summer in Death Valley.
