Fuel Tank Options
Senior User
Joined: Jun 2000
Posts: 185
Likes: 2
From: Milwauke WI
If you install a Aluminum Auxiliary Truck Diesel fuel tanks - Aluminum Tanks and Tank Accessories the fuel from the auxiliary tank will enter in the return line (yes return line) which is before the factory tank. The DTE will always be accurate.
They are great tanks. I had one in my 2008 F350 for 9 years and I just received a 55 gallon for my 2017 F450.
Good luck. Enjoy the road.
bigdon68
They are great tanks. I had one in my 2008 F350 for 9 years and I just received a 55 gallon for my 2017 F450.
Good luck. Enjoy the road.
bigdon68
The DTE calculator has no way of knowing how much fuel is in the Auxiliary fuel tank. It won't be correct, until the Auxiliary fuel tank is empty.
Freshman User
Joined: Nov 2011
Posts: 28
Likes: 0
I went with the 50g Titan tank. Love the double range, even though I too was disappointed that I had to mod it. I wanted the diesel and the short bed but wanted realistic range. FORD didn't offer that so knowing that in advance I decided to purchase the truck anyway. Doesn't mean I wasn't frustrated with FORD for not offering it.
It's my 3rd Ford truck in 6 years, first was a lemon, second was meh, and this one is pretty good with a handful of tradeoffs. The backseat area is disappointing after having an F150 previously. The tank size was ridiculous. But having the 350 while pulling the 5er is a great combination!
It's my 3rd Ford truck in 6 years, first was a lemon, second was meh, and this one is pretty good with a handful of tradeoffs. The backseat area is disappointing after having an F150 previously. The tank size was ridiculous. But having the 350 while pulling the 5er is a great combination!
Senior User
Joined: Jan 2007
Posts: 322
Likes: 3
From: Churchville, Maryland
The auxiliary tank pumps fuel into the FACTORY tank. The DTE reads off of the factory tank. The DTE constantly updates and is ALWAYS correct.
bigdon68
More Turbo
Joined: Sep 2016
Posts: 618
Likes: 6
If you have 30 gallons in the factory tank and a 100gal auxiliary- the truck will say DTE of about 360 Miles (12mpg in this example).
It has no idea you have another 100 gallons of fuel in the bed.
If you keep feeding fuel into the main from the aux (gravity while you drive) - your DTE wont be correct until the aux is completely exhausted and your on actual internal fuel. Then you have a full internal fuel tank, and the DTE will be correct. You'll never know when that is though until the needle starts moving and your actually drawing down the fuel in that tank.
With a Titan tank, after reprogramming the computer, the truck knows it has a 50 or 68 gallon tank depending on model- so the DTE will read 600miles (50 gallon tank, 12mpg in this example) or 816 miles (68 gallon tank, 12mpg in this example). Most of our trucks get better then that highway obviously, so the numbers would be higher.
Logistics Pro
Joined: Jul 2002
Posts: 4,821
Likes: 19
From: South Dakota
i love my titan tank.
Not worried about selling my truck with it as I'm not motivated to buy the current hideous poorly designed crop of ford trucks.
If i decide to buy one of the remaining '16's I'll just have the dealer swap tanks.
Not worried about selling my truck with it as I'm not motivated to buy the current hideous poorly designed crop of ford trucks.
If i decide to buy one of the remaining '16's I'll just have the dealer swap tanks.
FTE Leadership Emeritus
Joined: May 2014
Posts: 27,352
Likes: 5,946
From: Lake Hartwell, GA
Good call! I used mine just yesterday and filled up while going 65 MPH down the highway. 75 gallons of fuel gets me nearly 1400 miles unloaded and 900 miles with the 5th wheel. All of this with a tank that fits under the bed rails, so a 5th wheel and cover for the bed are no problems at all.
Senior User
Joined: Jan 2007
Posts: 322
Likes: 3
From: Churchville, Maryland
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Posting Guru
Joined: Dec 2015
Posts: 1,040
Likes: 9
Hey folks... what is the most economical option to get more fuel on board? My towing range sucks, I can not believe that Ford put this tiny 26 gallon tank in any Diesel Super Duty. I shouldn't have to buy a long bed to get more fuel tank. And I don't want to put a fuel tank in my bed, that looks ridiculous.
Laughing Gas
Joined: Dec 2015
Posts: 889
Likes: 38
"...reset on its own" must have been Chevy trained.
Mountain Pass
Joined: Nov 2005
Posts: 162
Likes: 0
From: Las Cruces, NM
I have the RDS 45 gallon tank. It only takes up nine inches of bed space. It gravity feeds into the filler tube. I went with the manual valve for a while, then installed an electric valve controlled by one of the upfitter switches. I turn it on after about 10 gallons used and have never had a problem with it. I experimented with turning it on and leaving it on when both tanks were full (I only put 40 gallons in the aux tank--supposed to only fill it 90% full). The indicator was pegged at F until I had used 40 gallons and then it started to decrease.
I get about 10 miles per gallon. Starting with 75 gallons of fuel tells me I can go about 750 with what I have on board. I don't use the DTE so I don't care what it says. I can keep up with the gallons used, subtract it from 75 in my head, multiply by 10 and have my own DTE.
This is the second truck I've had this tank in. If I get another truck, it'll go to that one. Total cost: around $700.
I get about 10 miles per gallon. Starting with 75 gallons of fuel tells me I can go about 750 with what I have on board. I don't use the DTE so I don't care what it says. I can keep up with the gallons used, subtract it from 75 in my head, multiply by 10 and have my own DTE.
This is the second truck I've had this tank in. If I get another truck, it'll go to that one. Total cost: around $700.
Laughing Gas
Joined: Oct 2016
Posts: 1,074
Likes: 91
From: DFW, Texas
I too did the in the bed fuel tank. Mine is an RDS 60 gallon tank with a 'mini' tool box on the top. Its great for storing tarps, gloves rope etc. the tank also sits flush with the bed rails. Mine is setup to pump fuel into the stock tank. I have a switch in the cab. Here are some old pictures of when I had this installed in my old truck.
Laughing Gas
Joined: Dec 2015
Posts: 889
Likes: 38
My 33 gal RDS aux tank is mounted in the bed and is gravity fed into the filler neck to the main tank. The DTE is just confused until I drain the aux tank. I just use one of the trip odometers to keep track of gals used and that seems pretty accurate compared to actual gal pumped when I fill up one or both.
New User
Joined: Jun 2017
Posts: 18
Likes: 1
KSM Marine may not be the most economical, but after buying one I would never go any other way. They have true aux fuel tanks that work with your factory gauge, not transfer tank setups that save you a couple hundred bucks and end up leaking fuel all over