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Author Topic: Auxiliary fuel tanks  (Read 1605 times)

Lynx0849

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Auxiliary fuel tanks
« 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
Rob & Deryl, Nettle, Tigger & Mai
Clyde, a 2015 RAM 3500 Cummins Longhorn SRW w/ARE cap
14í V nose utility trailer as mini toy hauler (for now)
N1ICB (Nursing 1 Ice Cold Beer)

msw3113

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  • Posts: 197
Re: Auxiliary fuel tanks
« Reply #1 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.
09 Carriage Cameo 32 SB2
11 Silverado K3500 HD LB DRW

Roy M

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Re: Auxiliary fuel tanks
« Reply #2 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.

HueyPilotVN

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Re: Auxiliary fuel tanks
« Reply #3 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.
Bill Waugh
40' Country Coach DP
2 Jeep Commanders
Mustang Bracket Race Car
Retired from the road to Lake Havasu after 35 years on the road

grashley

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  • Western KY for now.
Re: Auxiliary fuel tanks
« Reply #4 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.
Preacher Gordon, DW Debbie
09 Grand Junction 35 TMS  Progressive HW50C
Andersen Ultimate hitch
2013 F350 Lariat LB SRW Supercab diesel 4X4   TST TMS  Garmin 760
Nimrod Series 70 popup (sold)
It's not a dumb question if you do not know the answer.

coxid

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Re: Auxiliary fuel tanks
« Reply #5 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.
2017 GMC 3500 4X4 Denali Duramax Short Bed
2019 Outdoor timber Ridge 24RKS

Gizmo

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Re: Auxiliary fuel tanks
« Reply #6 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.
Regards, Bruce, Lin An, Kenji & Suki
2015 Ram Big Horn 3500 CC Cummins TD Dually 3:73 Gears & AISIN Tranny
2019 Grand Design Solitude 310GK-R

Roy M

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Re: Auxiliary fuel tanks
« Reply #7 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.

shorts

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  • Exploring the USA!
Re: Auxiliary fuel tanks
« Reply #8 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
Vicki and Mark Shorter
2015 Forrest River Blue Ridge RS3600 5er
2015 Dodge Ram 3500 dually 4wd
On the road fulltime!

Lynx0849

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Re: Auxiliary fuel tanks
« Reply #9 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
Rob & Deryl, Nettle, Tigger & Mai
Clyde, a 2015 RAM 3500 Cummins Longhorn SRW w/ARE cap
14í V nose utility trailer as mini toy hauler (for now)
N1ICB (Nursing 1 Ice Cold Beer)

touchracing

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  • Prepping for full time
Re: Auxiliary fuel tanks
« Reply #10 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. 
Wherever I may roam

2015.5 Chevy 3500 Duramax Dually
2014 Avenger ATI 26BB

coxid

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Re: Auxiliary fuel tanks
« Reply #11 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.
2017 GMC 3500 4X4 Denali Duramax Short Bed
2019 Outdoor timber Ridge 24RKS

1blue78

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Re: Auxiliary fuel tanks
« Reply #12 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.
2020 25Y Arctic Fox (on order)
2017 GMC 3500 SRW SLT L5P

Metalman RVer

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Re: Auxiliary fuel tanks
« Reply #13 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.

1blue78

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Re: Auxiliary fuel tanks
« Reply #14 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. 
2020 25Y Arctic Fox (on order)
2017 GMC 3500 SRW SLT L5P

Metalman RVer

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Re: Auxiliary fuel tanks
« Reply #15 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.

Chakara

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Re: Auxiliary fuel tanks
« Reply #16 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.
« Last Edit: October 26, 2019, 07:25:14 PM by Chakara »
2018 Arctic Fox 27.5L
2015 Chevy 3500 Dually LTZ

SeilerBird

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Re: Auxiliary fuel tanks
« Reply #17 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.

FL-Joe

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Re: Auxiliary fuel tanks
« Reply #18 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.
Full Time Traveling This Great Country!
Newmar Ventana 4369
Toad:  enclosed (Mini Cooper & Harley TG)
U.S. Army VN 71-72 (64B20)

lone_star_dsl

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Re: Auxiliary fuel tanks
« Reply #19 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.
2007 KZ Sportsman 36SE3 Toy Hauler
2016 Ram 3500, CTD, Aisin, Dually
Monument, CO

Hanr3

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Re: Auxiliary fuel tanks
« Reply #20 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.
2016 F150 3.5L Ecoboost XLT
2019 K-Z 231RK Sportsmen
1997 16' Sylvan Back Troller Select

Gizmo

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Re: Auxiliary fuel tanks
« Reply #21 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.   
Regards, Bruce, Lin An, Kenji & Suki
2015 Ram Big Horn 3500 CC Cummins TD Dually 3:73 Gears & AISIN Tranny
2019 Grand Design Solitude 310GK-R

FL-Joe

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Re: Auxiliary fuel tanks
« Reply #22 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. 
Full Time Traveling This Great Country!
Newmar Ventana 4369
Toad:  enclosed (Mini Cooper & Harley TG)
U.S. Army VN 71-72 (64B20)

grashley

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  • Western KY for now.
Re: Auxiliary fuel tanks
« Reply #23 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?
Preacher Gordon, DW Debbie
09 Grand Junction 35 TMS  Progressive HW50C
Andersen Ultimate hitch
2013 F350 Lariat LB SRW Supercab diesel 4X4   TST TMS  Garmin 760
Nimrod Series 70 popup (sold)
It's not a dumb question if you do not know the answer.

Gizmo

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Re: Auxiliary fuel tanks
« Reply #24 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.
Regards, Bruce, Lin An, Kenji & Suki
2015 Ram Big Horn 3500 CC Cummins TD Dually 3:73 Gears & AISIN Tranny
2019 Grand Design Solitude 310GK-R

BigLarry

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Re: Auxiliary fuel tanks
« Reply #25 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.
Larry and Betty
Bryan, Texas
2017 GMC Sierra 2500HD 4x4 Diesel
2016 Cougar 28RLS

Rob VanVoorhis

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Re: Auxiliary fuel tanks
« Reply #26 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!
Rob VanVoorhis
2017 Ford F250 Power Stroke
2019 Montana High Country 375FL
Awesome Wife & Tillie Our Yorkie
Retired
USN Vietnam Era

lone_star_dsl

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Re: Auxiliary fuel tanks
« Reply #27 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.
2007 KZ Sportsman 36SE3 Toy Hauler
2016 Ram 3500, CTD, Aisin, Dually
Monument, CO

lone_star_dsl

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Re: Auxiliary fuel tanks
« Reply #28 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.
2007 KZ Sportsman 36SE3 Toy Hauler
2016 Ram 3500, CTD, Aisin, Dually
Monument, CO

bigdon68

  • Posts: 3
Re: Auxiliary fuel tanks
« Reply #29 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
Bigdon68

2016 Mobile Suites 38RSSA Chestnut Dunes, FB Paint, induction cook top, solar, Cheap Heat, 3" Riser, WiFi Ranger, 4150 Pin
2017 F450 Lariat, CC, LB, 6.7, Camper/Snow Plow Pkg., Chrome Pkg., Retrax Bed Cover, TS3 Air Hitch, spray bedliner, bed lights, 55 gal. aux. tank, 200 psi air system