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RVing message boards => Trailers & Fifthwheels => Topic started by: Lynx0849 on October 07, 2019, 04:36:58 PM

Title: Auxiliary fuel tanks
Post by: Lynx0849 on October 07, 2019, 04:36:58 PM
I am thinking that for long trips it may make sense to have an auxiliary fuel tank to extend our range. A tank that more or less doubles what the stock tank can do seems as if it might not occupy too much of the truck bed.

I would love the thoughts from those of you who have done this.

Best case would be a tank that could come out when the 5th wheel isnít going to be used for a while.

Thanks
Title: Re: Auxiliary fuel tanks
Post by: msw3113 on October 07, 2019, 06:02:08 PM
Watching this thread, pretty sure I'd like to do the same.

Two acquaintances have auxiliary tanks in their Ram pickups.  They're plumbed right into the fill pipe and work via gravity so no pump needed.  Can't do that with GM products, it confuses the computer.

Keep an eye on dimensions: a hard tonneau cover will limit how tall the auxiliary tank can be.
Title: Re: Auxiliary fuel tanks
Post by: Roy M on October 07, 2019, 06:37:02 PM
I too have a Cummins pulling a fiver, I really see no need for extra tank(s) as I can run all day on one fillup if necessary as long as I keep my fat foot out of it. Besides, I need get out and stretch with a coffee time, 12-14 hour days behind the wheel are long behind me.
Title: Re: Auxiliary fuel tanks
Post by: HueyPilotVN on October 07, 2019, 07:10:39 PM
I have had three vehicles with auxiliary fuel tanks.

They do give you a feeling of comfort regarding running out of fuel.

My latest one is on my Jeep Commander.  I carry 55 gallons.

Mine is for long expedition trail rides.

I am the mobile gas station for my buddies.  Of course the gas is $20 a gallon way out at the end of the trail.

Maybe even $30 if you are really far off the trail, but then you start losing buddies.
Title: Re: Auxiliary fuel tanks
Post by: grashley on October 07, 2019, 07:19:40 PM
A key phrase in your question was  " a tank that could come out when the 5th wheel isnít going to be used for a while."  The tank and even 50 gal of fuel can add over 400#, and lower payload by that amount.  For some, that would run a SRW truck over weight when towing a FW.  Taking the tank out cures the problem.
Title: Re: Auxiliary fuel tanks
Post by: coxid on October 07, 2019, 07:30:06 PM
Have you ever considered a DIRECT REPLACEMENT tank? They remove your stock tank and bolt the replacement tank in its place! No extra fuel lines, no extra valves, only one fill location your fuel level gage works etc. Doesnít reduce the bed space. Aero tanks in San Bernardino, CA and Transfer Flow both make them and probably the are others.

They will almost double your fuel capacity (depending on the truck brand/LB/SB etc) I had Aero Tanks install their 60gal replacement tank in both my Ď98 and Ď07 Ram Cummins.

Now, will you ever re-capture the cost of the tank? You can rough in some numbers to get an idea. Re-capture or not when traveling xcountry it is sure nice to by-pass the expensive fuel states/cities.

BTW- I think that DOT considers it illegal to plumb an aux tank into the stock tank fill lines. If so I am sure that in case of an accident your insurance Co. would frown on it. Just something to look into.
Title: Re: Auxiliary fuel tanks
Post by: Gizmo on October 07, 2019, 08:30:03 PM
I am on the fence on installing an auxiliary fuel tank because we are planning a trip to Alaska in 2020, where as I understand there can be long distances between fuel stops in some areas.  Secondly and for the longer term, having an auxiliary tank would enable us to buy extra fuel at lower prices before travel into higher price fuel markets.
Title: Re: Auxiliary fuel tanks
Post by: Roy M on October 08, 2019, 12:54:22 AM
There are long distances between stops but nothing that the stock tank won't handle with proper planning. Once you leave the lower 48 fuel is darned expensive wherever you go and it gets worse as you travel north. A fill up in Whitehorse will have your cc running for cover.
Title: Re: Auxiliary fuel tanks
Post by: shorts on October 08, 2019, 07:21:30 AM
We went with switching out the stock tank for a larger tank rather than adding an auxiliary tank. That larger tank sure came in handy traveling thru Canada and Alaska this summer. Especially Canada where fuel prices varied widely from place to place. With a hard tonneau cover, we wanted to keep the space for the toolbox and other things.

Vicki
Title: Re: Auxiliary fuel tanks
Post by: Lynx0849 on October 08, 2019, 08:17:53 AM
I would expect that a long bed truck has more room underneath than a standard bed so a larger tank could fit.

Is there room for a larger tank on a standard bed 3500?

Since on some models, there are factory optional larger tanks too, the factory must be able to calibrate the fuel range guesser to various tank sizes.

If you install a larger after market tank, can the the new tank size be programmed in? By the dealer or tank installer?

Aside from the tank makers listed above, who else makes em?

Thanks
Title: Re: Auxiliary fuel tanks
Post by: touchracing on October 08, 2019, 09:03:26 AM
I installed 50 gallon Titan in bed auxiliary tank for a few reasons.  First I have a long bed dually so space and weight are not a concern.  Second the Titan replacement tank would gain 24 gallons for $1500.  The 50 gallon auxiliary was $1100.  Third I feel gravity fill auxiliary tanks are a fuel spill waiting to happen.  Titan comes with an electric fuel pump, filter, and control module. 

My main reason for wanting extra capacity was to be able to get anywhere I'm going without having to get fuel wile hooked to my camper. 
Title: Re: Auxiliary fuel tanks
Post by: coxid on October 11, 2019, 04:43:23 PM
Concerning the Replacement Fuel Tank level sender issue. Yes the replacement fuel tank is a few inches deeper (Aero has a skid plate available, I didnít require it)

I am going on memory now, (from 2007-2008) Aero Tanks uses your original fuel pick up, then ADDS extensions to its OA length which lowers the pick up down to the bottom of the replacement tank. This means that you will go a couple hundred miles (depending on load) on a a full tank before the gage even comes off of the FULL mark, thatís OK by me, itís near the ďEĒ mark that I am interested in! What the other replacement tank manufacturers do, I donít know. I had Aero install their tanks in their CA shop in my 2 previous trucks.

For the capacity of a replacement tank for YOUR truck you will have to call the manufacturer with the specifics of your truck for what size they have available.
Title: Re: Auxiliary fuel tanks
Post by: 1blue78 on October 26, 2019, 10:58:26 AM
I have a DeeZee combo fuel/tool box.  Holds 46 gallons (164L) and it is plumbed into the fill line of my 2017 3500 GMC.  I don't have any issues with the fuel gauge - I have heard that you need to let your fuel level drop so the truck doesn't see it sitting at full for too long. I usually let it run down to 1/2 then turn on my 30 GPH pump (which is also connected to a normally closed solenoid).  When the gauge reads about 3/4 I shut it off and the gauge tend so to keep rising to about 7/8 full.
Title: Re: Auxiliary fuel tanks
Post by: Metalman RVer on October 26, 2019, 03:50:08 PM
I installed this tank a while back & just love having the extra fuel on board; makes the box a bit smaller but it is nice only having to fill up once a month!

Haven't pulled the RV since installing it, but it is ready to go when we do!

I have a switch on the dash with an indicator light to show me when the solenoid is open & fuel is flowing, filling the truck tank.
Title: Re: Auxiliary fuel tanks
Post by: 1blue78 on October 26, 2019, 05:46:28 PM
 Nice tank Metalman.  From the photos it looks like you have run the fuel and vent lines through the box without grommets or bulkhead connector.  Over time you may wear a hole in the line. 
Title: Re: Auxiliary fuel tanks
Post by: Metalman RVer on October 26, 2019, 06:35:26 PM
Nice tank Metalman.  From the photos it looks like you have run the fuel and vent lines through the box without grommets or bulkhead connector.  Over time you may wear a hole in the line.

I suppose that may be possible.  At least with the "in-line" solenoid it is isolated when the switch is in the off position.  Not a bad idea though.
Title: Re: Auxiliary fuel tanks
Post by: Chakara on October 26, 2019, 07:22:23 PM
Like some of you I wanted more range.  But I also wanted a lot of storage in the bed which all the combo tanks I could find did not have.  Ended up installing this setup.


I set it up with the fill on the right and the pump on the left.   The trunk tank filler is on the left.  Most trips I get home and refill the trunk from the bed tank and then go and fill the bed tank.  I've even been filling the bed tank at the station while at the same time pumping from the bed tank to the truck tank.  Odd I know.  But end of the day, it works well for me.


-Chak


PS: I can't wait for the day where forums manage picture sizes for you.  Highly discouraging to post pics (which most would say are helpful) when you have to spend 5-10 minutes getting it to a format they will accept.  And every forum is different.   One more reason Facebook in winning.
Title: Re: Auxiliary fuel tanks
Post by: SeilerBird on October 26, 2019, 07:29:15 PM
Like some of you I wanted more range.  But I also wanted a lot of storage in the bed which all the combo tanks I could find did not have.  Ended up installing this setup.


I set it up with the fill on the right and the pump on the left.   The trunk tank filler is on the left.  Most trips I get home and refill the trunk from the bed tank and then go and fill the bed tank.  I've even been filling the bed tank at the station while at the same time pumping from the bed tank to the truck tank.  Odd I know.  But end of the day, it works well for me.


-Chak


PS: I can't wait for the day where forums manage picture sizes for you.  Highly discouraging to post pics (which most would say are helpful) when you have to spend 5-10 minutes getting it to a format they will accept.  And every forum is different.   One more reason Facebook in winning.
It should not be taking more than one minute to resize a photo. Open it up in any photo editor and change the horizontal dimension to 1000 px, click resize and then save with a new file name. Works every time.
Title: Re: Auxiliary fuel tanks
Post by: FL-Joe on October 27, 2019, 09:09:00 AM
The first year we were full time in our fiver our small tank on our F350 made some planning interesting out west.  We never had any issues but I found I had to run my tank lower than I wanted to.  Started looking at options.  Didn't want to spend a ton of money.  Didn't want to consistently haul an extra 150 to 250 pounds of weight when not needed.  Plus I didn't want to give up any more room in my PU bed than I had to.

Ended up using four 5-gallon diesel cans with easy-pour spouts.  They fit nicely in my tool box and I only filled them when I knew the extra capacity was going to be needed.
Title: Re: Auxiliary fuel tanks
Post by: lone_star_dsl on October 28, 2019, 09:01:00 PM
I have a 105 gallon auxiliary tank in my truck. It makes a world of difference not only in range, but I can now take my time when shopping for diesel so that I can get the best price. For every penny cheaper I can find fuel, I save $1.00 on the total fill up. It really pays to search for the cheapest fuel. When we go to the beaches in California, I can top up everything and not have to pay the state's huge fuel prices.

When towing, my truck gets about 8 mpg leaving me with about 220 miles of usable range. With the auxiliary tank, I can push it to the limit, pull over to transfer fuel and stretch legs, then get back on the road. Over a day of driving, this can save me 20-30 minutes.
Title: Re: Auxiliary fuel tanks
Post by: Hanr3 on October 28, 2019, 09:59:01 PM
I looked into an auxiliary tank. However, the misses and I have to make pit stops long before the truck needs fuel. Plus it gives me time to stretch the legs and let the dogs water the grass. Besides- you get to experience novelty items local to that region that you would miss if you kept on trucking.
Title: Re: Auxiliary fuel tanks
Post by: Gizmo on October 28, 2019, 10:34:30 PM
I looked into an auxiliary tank. However, the misses and I have to make pit stops long before the truck needs fuel. Plus it gives me time to stretch the legs and let the dogs water the grass. Besides- you get to experience novelty items local to that region that you would miss if you kept on trucking.

Your travel plan mirrors ours exactly, right down to needing to give the dogs a break and I agree, but we have traveled in many places where fuel stops are few and far between including planning a trip to Alaska and Canada so having the extra fuel is a plus.  Also it may give the option of not stopping for fuel at a more expensive stop when a less expensive option may be just ahead.   
Title: Re: Auxiliary fuel tanks
Post by: FL-Joe on October 30, 2019, 07:56:18 AM
I have a 105 gallon auxiliary tank in my truck. It makes a world of difference not only in range, but I can now take my time when shopping for diesel so that I can get the best price. For every penny cheaper I can find fuel, I save $1.00 on the total fill up. It really pays to search for the cheapest fuel. When we go to the beaches in California, I can top up everything and not have to pay the state's huge fuel prices.

When towing, my truck gets about 8 mpg leaving me with about 220 miles of usable range. With the auxiliary tank, I can push it to the limit, pull over to transfer fuel and stretch legs, then get back on the road. Over a day of driving, this can save me 20-30 minutes.

Did you ever try to figure out if hauling an extra 700 pounds or more of fuel weight decreased your mpg to rob you of a good portion of that savings?

I recently asked a buddy about putting an auxiliary tank on his F350.  He hauls for a couple different RV manufacturers out of northern Indiana, putting about 60,000 or more miles on a year.  He said he can fuel up and be in and out of a truck diesel lane in less than 15 minutes plus he has to stop every 3 or 4 hours anyway. 
Title: Re: Auxiliary fuel tanks
Post by: grashley on October 30, 2019, 08:35:33 PM
I have a 105 gallon auxiliary tank in my truck. It makes a world of difference not only in range, but I can now take my time when shopping for diesel so that I can get the best price. For every penny cheaper I can find fuel, I save $1.00 on the total fill up. It really pays to search for the cheapest fuel. When we go to the beaches in California, I can top up everything and not have to pay the state's huge fuel prices.

When towing, my truck gets about 8 mpg leaving me with about 220 miles of usable range. With the auxiliary tank, I can push it to the limit, pull over to transfer fuel and stretch legs, then get back on the road. Over a day of driving, this can save me 20-30 minutes.
What does that extra 700 lbs of fuel (plus the tank) do to your available Payload?
Title: Re: Auxiliary fuel tanks
Post by: Gizmo on October 31, 2019, 01:13:23 PM
What does that extra 700 lbs of fuel (plus the tank) do to your available Payload?

It will reduce the payload capacity as will any added weight, but the OP's signature indicates a DRW 1-ton which has considerably more payload capacity than a SRW.  I do not know the OP's specific numbers but having general knowledge of weights, capacities etc. I would hazard a guess he would be ok.  This is a good case for not selecting a truck with only enough or a small margin in payload capacity.
Title: Re: Auxiliary fuel tanks
Post by: BigLarry on October 31, 2019, 10:39:36 PM
I use a Transfer flow 75 gallon auxillary tank and love it.  Moved it over from my 2007 Chevy Diesel.   I did have to get a new brain for the system from Transfer Flow.  Since I'm pulling a TT, I don't have a problem with load capacity.  With 110 gallons on board I've been able to fuel up when its convenient and try to use Gas Buddy to save some $ whenever possible.  It really was great on our Alaska Trip.  We were able to save some big $ by planning our fuel stops.
Title: Re: Auxiliary fuel tanks
Post by: Rob VanVoorhis on November 01, 2019, 06:07:41 PM
I have a 60 gal gravity feed reserve diesel tank in my 2017 F250 short bed with an auto slide hitch, gives me a 1000 mile range when pulling and 1500 miles if just running the highway. Fill quick in the truck fuel lanes that have the wide mouth nozzles, love it, much peace of mind!
Title: Re: Auxiliary fuel tanks
Post by: lone_star_dsl on November 11, 2019, 12:42:57 PM
What does that extra 700 lbs of fuel (plus the tank) do to your available Payload?

With a FULL trailer (water, toys, etc.)and a truck full of kids, my weights are:

Front axle: 5,200
Rear axle: 7,740
GVW: 12,940

According to Ram, my truck has the following capacities:

Front axle: 6,000
Rear axle: 9,750
GVWR: 14,000

With the fuel at an added 700 lbs, I'm still 360 lbs under the GVWR and well under the axle ratings.
Title: Re: Auxiliary fuel tanks
Post by: lone_star_dsl on November 11, 2019, 12:50:26 PM
Did you ever try to figure out if hauling an extra 700 pounds or more of fuel weight decreased your mpg to rob you of a good portion of that savings?

I recently asked a buddy about putting an auxiliary tank on his F350.  He hauls for a couple different RV manufacturers out of northern Indiana, putting about 60,000 or more miles on a year.  He said he can fuel up and be in and out of a truck diesel lane in less than 15 minutes plus he has to stop every 3 or 4 hours anyway.

If there is a MPG penalty, it doesn't make itself noticeable out to the second decimal place.

If I were hauling commercially, I would want to take as much fuel as possible for economic reasons. The savings really add up when you can buy cheaper fuel in bulk. It can sometimes be $5-10 a day when you get away from fueling at the large truck stops. $100+ dollars a months in fuel savings really start to add up.
Title: Re: Auxiliary fuel tanks
Post by: bigdon68 on December 03, 2019, 11:38:31 AM
We have a 55 gallon (under bed cover) auxiliary tank in our F450.  This gives us a total capacity of 103 gallons.

This is the second tank we have gotten from Aluminum Tank and Truck Accessories, https://www.attatank.com/, and they work very well.  They have what they call the Freedom Fill System which is plumbed into your tank lines and your gauge wire from the tank.  When your factory tank gets to 3/4 of a tank -- a pump comes on automatically and fills the tank from the auxiliary tank.  There is a gauge on the auxiliary tank that tells you how much is in there.

Great instructions.  I have put both of these tank in our trucks.

As has already been said -- it gives you the freedom to pick when you get fuel -- not being held hostage by the fuel gauge. 

With a 103 gallons I can travel wherever we need to go before I get fuel. 

Great investment.

bigdon68

2017 F450
2016 DRV Mobile Suites 38RSSA
Title: Re: Auxiliary fuel tanks
Post by: WannaBeRVing on December 28, 2019, 07:02:55 PM
The first year we were full time in our fiver our small tank on our F350 made some planning interesting out west.  We never had any issues but I found I had to run my tank lower than I wanted to.  Started looking at options.  Didn't want to spend a ton of money.  Didn't want to consistently haul an extra 150 to 250 pounds of weight when not needed.  Plus I didn't want to give up any more room in my PU bed than I had to.

Ended up using four 5-gallon diesel cans with easy-pour spouts.  They fit nicely in my tool box and I only filled them when I knew the extra capacity was going to be needed.


I'm also looking at adding fuel capacity and like this option because of payload limits and cost.  Are there no safety concerns with the tanks in the bed of your truck?  Or do you keep it in the storage area of your RV?
Title: Re: Auxiliary fuel tanks
Post by: 1blue78 on December 29, 2019, 09:31:36 AM


I'm also looking at adding fuel capacity and like this option because of payload limits and cost.  Are there no safety concerns with the tanks in the bed of your truck?  Or do you keep it in the storage area of your RV?


There are no safety concerns if you are using approved storage tanks.  It will be a PITA pouring from the fuel tanks though - in bed aux tank is way easier and if you don't want to pack around extra weight when you don't need it, don't fill it.  I always fill from the aux tank into my main tank.  This keeps the fuel in the aux tank fresh and since I have a water blocker filter on the line coming from my aux tank I get clean fuel in my main tank.
Title: Re: Auxiliary fuel tanks
Post by: Warboar on January 03, 2020, 01:59:53 AM
I have thought about adding an aux. tank but with my Ford I now have a 48 gallon fuel tank and it does just fine.  With my RAM and the 30 gallon tank I was wanting the aux. tank but with the short bed I just didn't have the room for my hitch or if I wanted to put one of my 4wheelers up in the bed.  I could do the aux. tank in the Ford but I just don't see the need at this point in time.  If things were to change and I was spending more time on the road then yeah I would certainly consider it.   
Title: Re: Auxiliary fuel tanks
Post by: dufferDave on January 06, 2020, 12:24:36 AM

There are no safety concerns if you are using approved storage tanks.  It will be a PITA pouring from the fuel tanks though - in bed aux tank is way easier and if you don't want to pack around extra weight when you don't need it, don't fill it.  I always fill from .........

I like the option and flexibility of having some extra gas, and I use a couple 5-gal plastic tanks also. I don't like using the pour spouts, though, to xfer from those tanks into the RV's gas port, so I have a HF gasoline transfer pump/stick (costs like $8, runs on two D-cells) that I can rest a 5-gal tank on the RV's rear bumper and squirt the gas cleanly into the RV.

Title: Re: Auxiliary fuel tanks
Post by: Gizmo on March 12, 2020, 12:51:14 PM
I bit the bullet and brought my truck in to have a Titan 55-gallon replacement tank installed.  Can't wait to have the extended range, especially since we will be heading to Alaska late spring.
Title: Re: Auxiliary fuel tanks
Post by: Lynx0849 on March 12, 2020, 05:37:45 PM
I bit the bullet and brought my truck in to have a Titan 55-gallon replacement tank installed.  Can't wait to have the extended range, especially since we will be heading to Alaska late spring.

I look forward to hearing how it goes. Where are you having it done?
My truck is only the 6í6Ē bed so I think can only get a smaller tank than yours. Next will be a dually which I think is only an 8í bed if crew cab.

I wonder how the electronics will learn the tank capacity for estimating remaining range? Maybe it is a service computer setting that can be changed?
Title: Re: Auxiliary fuel tanks
Post by: Gizmo on March 12, 2020, 09:41:22 PM
I look forward to hearing how it goes. Where are you having it done?
My truck is only the 6í6Ē bed so I think can only get a smaller tank than yours. Next will be a dually which I think is only an 8í bed if crew cab.

I wonder how the electronics will learn the tank capacity for estimating remaining range? Maybe it is a service computer setting that can be changed?

Back from having the tank installed it went well only hiccup is when I went to fill up the tank and the pump stopped at $100.00, so had to run a second fill to completely fill it up.  I also purchased and had a tank bash plate that Titan offers.  I had it installed by Vision Diesel Performance in Aurora, OR near where we are currently located.  They install all kinds of diesel products and accessories and I believe also perform regular maintenance and repair services, I found them from the Titan website under dealer locator.  There is no adjustment for the fuel gauge to read correctly.
Title: Re: Auxiliary fuel tanks
Post by: steveblonde on March 13, 2020, 07:07:20 AM
Back from having the tank installed it went well only hiccup is when I went to fill up the tank and the pump stopped at $100.00, so had to run a second fill to completely fill it up.  I also purchased and had a tank bash plate that Titan offers.  I had it installed by Vision Diesel Performance in Aurora, OR near where we are currently located.  They install all kinds of diesel products and accessories and I believe also perform regular maintenance and repair services, I found them from the Titan website under dealer locator.  There is no adjustment for the fuel gauge to read correctly.

Titan makes a great product ive sold lots of them - my current Ford has a 181 liter tank which is 47.8 US gallons. you will love the extra range especially when some place are more expensive than others . Congrats
Title: Re: Auxiliary fuel tanks
Post by: Gizmo on March 13, 2020, 08:50:45 AM
Titan makes a great product ive sold lots of them - my current Ford has a 181 liter tank which is 47.8 US gallons. you will love the extra range especially when some place are more expensive than others . Congrats

Good to know and thanks.  I am really looking forward to that extra range, especially for our upcoming trip to Alaska and because of our travels in the west.