Auxiliary fuel/ toolbox combo

Rodbuster

Well-known member
Just bought a 2012 Key Largo and a F350 dually with the new 6.7 engine.
The existing fuel tank holds 37.5 gallons.

What does everybody think of adding a combination fuel/toolbox with a 60 gallon capacity to the long bed of my truck? (such as the RDS model# 72547)
I know the weight factor is not a plus, but the extra mileage is appealing.

Thank you
Rodbuster
 

davebennington

Senior Member
I agree adding the RDS combo tank is a good idea, I installed the RDS tank in our TV and it has worked well, the tool box is not very deep but it will hold a few essentials. We have the 60 gallon version and it lets you fuel up when you find fuel at a good price.

Dave
 

Ray LeTourneau

Senior Member - Past Moderator
I've thought about an extra tank but haven't yet bought one. I really like having the extra room and capacity in the truck to carry stuff that would otherwise take up room in the rig. I carry a tote with a 50 amp extension cord, sun screens for the awning and garden hose. And then there's my little Boliy Generator, gas can and the 20# LP bottle for my grill. (sounds like an explosion waiting to happen). I have a rear mounted low profile box for my extra tools and stuff. The rear mounted box, for me, is much easier to access.

As for the extra fuel, there are many good reasons to have it, but we've managed for 5 years without it so far. We rarely travel long enough in one stretch that we haven't been able to find fuel en-route.
 

katkens

Founding Illinios Chapter Leader-retired
I have a 40 gallon RDS tank /toolbox love it ,best bang for the bucks out there. I have alot less volume in my main tank than yours so a bigger help to me than you but is really nice being able to buy cheaper and not worry about finding a place to fuel. One thing to think about is the more fuel gallons it holds the less toolbox you will have ,if you really want to put stuff in it..........Kenny
 

ultrafarmer

Well-known member
I built a 73 gal tank and love it. I ran a 3/8 hose to the fill of the pickup tank and took out the metal spacer thing and welded a 3/8 hose nipple in it. I have a simple 1/4 turn valve at the tank and then can go very long time. I also look for cheaper fuel.
 

porthole

Retired
An alternative is a larger in frame tank. Titan makes a replacement 65 gallon tank. Leaves the bed open. Had one in my GMC, swapped out the stock 26 for a 52. Huge difference in traveling.
The 65 is on my list of things to do when the funds are available.

The real advantage is buying fuel when you want to, not because you have too.
 

TXBobcat

Fulltime
I had a 45 gal American combo tank installed with electric tank switch and uses the OEM Fuel Guage.

I found out that the tank helps give me the distance I want. I have tried to use it to purchase the best price diesel but that seems to elude me when on the road. It seems the station back 10 miles had the best price or once I fill up and am about 10 miles down the road I find one cheaper. So I just fuel up at the best local price and keep on truckin.

If you get to the Dallas Fort Worth area and are looking for a tank you might go by and see the American Tank Co.

BC
 

andyhill

Member
TXBobcat,

I know what you mean about filling up and then finding out that the lowest priced fuel was 10 miles back. I just pull over and drain that expensive fuel out and then fuel up with the cheaper. LOL

Andy
 
Last edited:

TXBobcat

Fulltime
Yea.. this would be like my daddy telling me that people might think I am dumb, just don't open my mouth and prove it. ... Haven't learned that yet. LOL... I feel like I would like to do that but them my wife would then know !!!!

BC
 

hoefler

Well-known member
I find it a lot easier to fill up after getting to our campsite and setting up. I have a 75 gal L-shaped tank under my tool box. I can usually get between 900 and 1100 miles between fill ups, depending on our driving conditions. Last trip was 3200 miles and only had to fill twice on the road.
 

jmgratz

Original Owners Club Member
Just a thought...Doesn't weight from all of the extra fuel play into the fuel mileage equation? If so by how much? and what are the cost differences? Don't know just thinking.....
 

Hastey

Oklahoma Chapter Leaders
I have a 60 gal RDS Fuel and Tool combo and love it. I have no noticed fuel economy decrease from the 60 gal extra weight. Use it for distance and fueling around the farm. RDS also sells the adapter kits to tie it to your trucks tank.
 

mikeandconnie

Well-known member
Best investment I made was my Aux Tank. I found out the hardway in the middle of the desert out of fuel. They really come in handy out west. I have a 800 mile range now and can fuel up once a day and normally at a station with a bulk DEF pump which is $2.20 a gallen verse $6.00 in the jug.
 
Last edited:

PUG

Pug
I had an alum tool box (new) so I built my own alum under toolbox tank. Added another 32 gallons. I put in RDS kit to T it into fuel filler hose and a manual shut off valve on side near bottom of tank. Also added "sight" hose on side of tank to see level of hose. Works great and helps on buying cheaper fuel. If I hadn't had an existing tool box I think the better way to go is a L type tank/toolbox combo. Not cheap but nice especially if you have 60+ more gallons Saw another guy that went to a wrecking yard and found a cheap tank out of a truck.
 

2psnapod2

Texas-South Chapter Leaders-Retired
Best investment I made was my Aux Tank. I found out the hardway in the middle of the desert out of fuel. They really come in handy out west. I have a 800 mile range now and can fuel up once a day and normally at a station with a bulk ECF pump which is $2.20 a gallen verse $6.00 in the jug.

What are you refering to when you say a "at a station with a bulk ECF pump which is $2.20 a gallen verse $6.00" I need to find that station with 2.20 a gallon.
 

mikeandconnie

Well-known member

hoefler

Well-known member
This is the third truck I have had this set up in. When I installed it in my 05, I did not experience any measurable difference in mileage. If there is any, I would not give up the extended range for anything.
 

jmgratz

Original Owners Club Member
Gosh, 400 pounds. Since I am already maxed out, I would have to kick out the dogs, DW, and tools to haul the extra fuel LOL
 

Cimriver

Well-known member
I put a 51 gallon Titan replacement tank on my truck. I have a short bed so didn't want to take up the room an in bed tank would use.

51 gallons in painful enough at the pump for me!
 
Top