Since diesels don't have evaporative vapor emissions on the fuel tank, there's no worry of raw fuel being drawn into that system. Can the fuel tank in the Super Duty be filled plum-full right up to the top of the filler neck? Volkswagen owners refer to this as "venting", and you can get up to 2 gallons more than the capacity of the fuel tank, which is another 100 miles! Obviously on a hot day you want to get driving right away to keep fuel expansion from occurring, but it could mean less stops with 30 to 40 more miles per tank.

 

Yes it can be done, but depending on where Ford actually put the tank and if the same tank is designed to work with Gas and Diesel will greatly change how much "extra" it can hold. I'm coming over from the Ram Diesel market and the tank vent mod, relocating the vent to the highest spot of the expansion chamber, could net 5-6 not gallons in the factory tank.

 

I do this at every fill up. No problems.

 

My motor skills would have me spilling diesel down my gorgeous black paint so I call 48 gallons good and walk away. lol

 

on my 2004 I've ALWAYS filled the factory tank to the brim (I fill it until I see liquid, not foam).

On my 2004 6.0L I performed the in-tank Harpoon Mod....The Harpoon Mod really accelerated the tank fill on the 6.0L

 

Glad this came up as I was wondering this myself. In past diesels I've always filled it right up to the top when traveling, trying to get every bit of additional miles per fuel stop.

But after joining here, I heard lot's of "No, don't fill it past the 2nd click off".

 

has anyone provided any concrete reason why it shouldn't be filled all the way?
when your burning a gallon every 12 or so miles it doesnt take long to pull the fuel down from the cap.

 

The idea of not filling to the top is true for gas powered vehicles as gasoline expands much more than diesel fuel. They have a system in the filler neck that takes dangerous gas vapors and dispenses them into a carbon filter. Overfilling them will send raw fuel into the carbon filter.
Diesel trucks don't have this system, so "fill it to the brim" if you have the time a patience to do so. For me, I do so to keep accurate records of fuel consumption.

 

I fill to the top at ever fill and have been since my first diesel back in '09.

On my current truck I can put 50 gal in the 48 gal tank....

 

[QUOTE=17 Oaks;17141585]
On my current truck I can put 50 gal in the 48 gal tank....[/QUOTE]

Go ahead Don, rub it in about that 48,,,no now its a 50 gallon tank! The short bed certainly got shorted in the fuel tank department, then to top it off they've made the fuel light come on about 75 miles sooner than it needs to which only give me about a 400-450 mile range if I'm not pulling. I wish Ford offered an optional extra capacity fuel tank. I certainly would have bought it.

 

I don't worry about filling it to the top and getting in every drop. I fill at a half tank for day to day driving (easier to stomach the bill) and when driving long distance I stop more often than 500 miles anyway and it gives me a chance to stretch and get a cold drink etc.

 

[QUOTE=RJC2;17142340]LOL, better it comes on early than comes on later...

My motorhome had a 150 gal diesel tank, on a trip I am about 20 mi outside El Paso when it shuts down, as if it was out of fuel...I check and no problem there I stull got fuel...or so I think. After some messing around I call tech support and we talk for a bit, try this, try that, wants to start but won't. Then I hear the DREADED words: 'Ohhh, I think they forgot to tell you'

TELL ME WHAT??

Well yes you have a 150 gal tank, but you can only access the first 100 gals and in make ready they should have checked to see if the computer was set for a 150 tank.

Is this some kind of sick joke???


That was the LAST STRAW, sold the beast, nevermore.

 

[QUOTE=17 Oaks;17142923]
Shorting you 50 gallons! Now that's a major mistake. You didn't use any foul language did you.... Nooooo!

 

Just got my truck, but thought I'd chime in with the"2nd click" method. First click at WFO on the nozzle. 2nd click on low speed fill rate, first notch on the filler handle. Not sure it adds enough fuel to matter since I'll never run the tank dry anyway...

 

Just tried this tonight for the first time. Who knew! Thanks for the tip!