Best way to increase fuel capacity

Romee

Member
We are looking to increase our fuel capacity in our 2018 Ram 3500. We are looking for input on which way we should go. Replace the existing 32 gallon tank with an aftermarket 50 OR install a 40 gallon in-bed tank? Thanks in advance for everyone’s input and reason why....
 

Oldelevatorman

Well-known member
Remember the more weight you put in the truck the less payload you have for towing weight. Did you need more fuel to drive a lot more miles a day or do you not like stopping for gas that much! We have a max of 300 miles a day so I don’t need the weight or the extra fuel, but that’s our style, retired and in no hurry! Good luck, I’m sure others will chime in!


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wdk450

Well-known member
Well, if price is no factor, I would go with the replacement 50 gallon tank. The fuel should be more protected and less exposed, there is no fuel transfer pumps or hoses involved, the extra fuel is under your truck not up on the bed where every lowlife fuel thief could get ideas. Looking at the outside of the truck nobody would guess that you have all this extra fuel investment. I hope you have a locking gas cap, although I know that they are just a slight deterrent to a lowlife stupid enough to drill into a fuel tank opening. We would see these characters on a regular basis in my hospital's burn unit.
BTW, I got a $1 can of green spray paint at WallyWorld and painted my locking diesel fuel cap green.
 

Romee

Member
With our trailer we average about 210 miles per tank pulling trailer so about 185 or so before refuel. The extra weight under or in bed is still within weight limits for the tow vehicle.
 

cookie

Administrator
Staff member
My RAM OEM tank is 32 gallons. I added a 60 gallon aux tank in the bed. I installed a solenoid actuated valve for the gravity fill controlled by a switch in the cab.
I like the added capacity.

Peace
Dave
 

JWalker

Northeast Region Director-Retired
32 gallon RDS auxiliary tank in bed. Gravity fed. Love the extended range. Biggest benefit is refueling without the trailer attached.
 

jnbhobe

Well-known member
I have a 60 gal RDS tank & toolbox in the bed setup like Cookie has and 48 under the truck, used this setup in my last three trucks.
 

SNOKING

Well-known member
Just slow down, and mileage and distance on the existing tank will go up. Buy a 6 gal yellow diesel can for emergencies.
 

NWILSON

Kentucky Chapter Leaders - retired
I installed a 60 gallon aux tank to eliminate the need for refueling at truck stops only. We unhook at the end of the day and then head to the best deal on fuel in the area.
The DW was concerned, however, that not stopping for fuel during the day would also mean not stopping for potty breaks!:cool:
 

RoadJunkie

Well-known member
We went with, what Transfer Flow calls, a mid-ship replacement, 50 gallon, tank. With Ford, the OEM gauge and DTE was reprogrammed for the new capacity capability. The bad part is that the tank goes with the truck when it is sold, the good part is my bed utility is not reduced by an auxiliary tank. Either way, Transfer Flow has well-built products and, if you sign up for email alerts, they typically have discounts available.
 

Romee

Member
We went with, what Transfer Flow calls, a mid-ship replacement, 50 gallon, tank. With Ford, the OEM gauge and DTE was reprogrammed for the new capacity capability. The bad part is that the tank goes with the truck when it is sold, the good part is my bed utility is not reduced by an auxiliary tank. Either way, Transfer Flow has well-built products and, if you sign up for email alerts, they typically have discounts available.
I am being told that RAM does not have the ability to reprogram the tank size from my 32 gallon to the 50 gallon... which is odd.. anyone have other information?
 
I installed a 50 gallon tank in the bed of the truck with gravity feed.
This gives me a total of 86 gal. Love it.
 

carl.swoyer

Well-known member
We are looking to increase our fuel capacity in our 2018 Ram 3500. We are looking for input on which way we should go. Replace the existing 32 gallon tank with an aftermarket 50 OR install a 40 gallon in-bed tank? Thanks in advance for everyone’s input and reason why....
I at one point was considering an additional fuel tank. Then I realized the extra capacity and weight wasn't necessary as I normally travel 150 to 180 miles a day. That being said I wondered what the actual advantage would be. I can top of easily , it's not an inconvenience. If you're burning more than 36 gallons of fuel per day your driving to long and not entirely enjoying the RV.
So I opted for topping off daily.

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chaplady

Well-known member
I have 60 gal aux in bed of truck, big advantage for me it gives me flexibility to pick n choose where to buy fuel thus saving money.
 

cookie

Administrator
Staff member
I wondered what the actual advantage would be.

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I can travel two or three days without fueling up.
After two or three days of travel we are ready to spend a couple days relaxing and at that point I can, like Chaplady, choose where I want to fuel up. Without the trailer.
The extra tank is not for everyone but I will not be without it.

Peace
Dave
 

NYSUPstater

Well-known member
Previous 2 trucks, I replaced the factory tank(30 gal?) with Transfer Flow 50 gal mid ship tanks. Sadly, they both went with the trucks as well when I parted ways. Both trucks were short box super duties. New steed came w/a 48 gal tank and so far happy w/ it. We ave around 9 mpg towing and on long trips, stop about 250-275/300 miles for fuel and potty break. I try to plan out fuel stops before leaving and adjust stopping distances accordingly. If you go w/ the in bed tank, best part is that it can be transferred to new truck. Like others have said, you'll need to figure out how much weight capacity you have left before adding the tank. A 1 ton SRW and good size trailer doesn't leave a whole lotta room left IMO. DRW will pretty much negate that problem.
 

Mark-Roberta 051995

Well-known member
I had a 50 gallon transfer in the bed on my '15 Ram and have now transferred this tank into the new '18 Ram. I put a solenoid with a switch on the first truck so I could turn off/on while driving if needed, but this new one I just did a straight gravity feed hose. We still stop for breaks but can purchase diesel at my price and location since I have 82 gallons. We use Kroger points throughout the summer to get that precious $1 per gallon off.

At 7 pounds per gallon I will carry an extra 350 pounds plus the weigh of the tank (40 lbs.) so I have no concerns on this. The tank is also low profile so I can keep my tonneau cover over it when I am not towing so no one sees it.

tonneau 2.JPGtank.JPG
 

DirtyMax88

Well-known member
We are looking to increase our fuel capacity in our 2018 Ram 3500. We are looking for input on which way we should go. Replace the existing 32 gallon tank with an aftermarket 50 OR install a 40 gallon in-bed tank? Thanks in advance for everyone’s input and reason why....

We have an in bed AUX tank. We went with a 115 gal., so we don't have much room in front of our 5th wheel hitch for anything except some leveling blocks (which I'm fine with). Ours works off a small pump, with a switch to turn it on and off in the cab. As many can relate, It really gives you the luxury to stop when/where you want. Maybe find a nice rest area or welcome center, instead of having to deal with truck stops or gas stations. We are not full timers or retired, so our vacations are usually 4-10 days depending on distance, so it's not unusual for us to travel 400-500 miles in one day. It's Hammer down and get there for us!!!!

I think it all depends on how much you value space in your bed and how much extra weight you can handle (you mention you have a 3500 Ram, but didn't say if it was SRW or DRW). Lots of AUX tank options out there.
 

avvidclif

Well-known member
I at one point was considering an additional fuel tank. Then I realized the extra capacity and weight wasn't necessary as I normally travel 150 to 180 miles a day. That being said I wondered what the actual advantage would be. I can top of easily , it's not an inconvenience. If you're burning more than 36 gallons of fuel per day your driving to long and not entirely enjoying the RV.
So I opted for topping off daily.

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Go visit out west. There are roads where available fill-ups are that far apart, much less rv parks.
 

SNOKING

Well-known member
We have been traveling back and forth for Washington to Arizona for the last 11 years. We have traveled a lot of different routes in those years. The 2001.5 RAM had 35 gal tank and smaller 5th wheel, and got better towing mileage than the 2015, which has a 32 gal tank. The 2015 does not get as good as mileage with 4-5000 pounds more GCW. We have made a couple round trips with it and never had to use the 6 gal extra I carried in a can. Now that DW has me NOT doing it in 3.5 days of driving, it is even less of an issue.

People with SRW trucks that add 50 gals of diesel, must not weigh their rigs. You look around the snowbird park and some of the trailers being towed with SRW trucks and say WHAT the!!! We weighed the 2015 and BH3575el several times and were fine. However I see lots of LM 365s that are heavier being towed with SRW trucks. Somehow just about all of them return each winter. Chris
 
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