A transfer tank for a truck is a DOT-certified secondary fuel container that mounts in the bed or on a service body, stores diesel or gasoline, and dispenses it to a generator, tractor, or machine through a pump, hose and nozzle. It is not plumbed into the truck’s own fuel system, which is the single fact that separates it from an auxiliary fuel tank and keeps it on the right side of the federal rules. If you are picking through the best transfer tanks for trucks in 2026, that distinction decides most of what comes next.
Contractors, landscapers, farmers, mobile mechanics, fleet operators and overlanders buy these tanks for the same reason: the job site is forty minutes past the last fuel stop, and paying a fuel delivery driver costs more than the equipment you are hauling. The tank sits in the bed, you run a hose to the machine, and you keep working. Our team has spent the last few months reading specifications, install write-ups and owner complaints across the RDS, Dee Zee, Better Built, UWS and VEVOR catalogs, and what follows is the result.
Two things surprise first-time buyers. The first is weight: diesel and gasoline both weigh about 6.7 pounds per gallon, so a 100-gallon tank is roughly 670 pounds before you add the tank itself. On a half-ton pickup that can eat most of the payload rating on the door jamb, and it also moves your center of gravity rearward in a way that changes how the truck handles. The second surprise is legality, because most people do not realize that an in-bed fuel container has to meet specific federal rules before it goes anywhere near a public road.
We used seven criteria to build this list: capacity matched to a real use case, verified DOT or EPA compliance language in the listing, material and weld quality, whether the footprint actually fits a bed, pump and dispensing hardware, warranty length, and how real owners describe the install. Nine tanks made the cut. We left out anything with a thin review history, anything sold without compliance documentation, and anything whose design pointed at a portable caddy rather than a truck bed.
Table of Contents
Top 3 Picks for the Best Transfer Tanks for Trucks in 2026
Dee Zee takes the top slot because it pairs the most review history in the group with heavy-gauge steel and a footprint that works in a standard bed. RDS 45-gallon aluminum earns the top rating for anyone who wants a rust-proof body in a shape that fits most beds, and Better Built wins on value because its overfill shutoff and mounting kit are features you normally pay extra for.
Dee Zee DZ92556NSB 42-Gallon
- 14-gauge alloy steel
- 5 stability baffles
- Mounting tabs
- 42 gallon capacity
RDS 71083 45-Gallon Aluminum
- Aluminum body
- Fully welded seams
- 45 gallon capacity
- Top siphon for gasoline
Better Built 36-Gallon Steel
- Overfill auto shutoff
- Built-in baffles
- 2-inch bungs
- Lockable vented cap
All Nine Transfer Tanks at a Glance (September 2026)
This table lists every tank in the roundup with the specs that decide the purchase. Capacities run from 36 gallons to 116 gallons, and one of the nine comes with a pump and hose included.
| Product | Specs | Action |
|---|---|---|
| Dee Zee DZ92556NSB 42-Gallon Steel Transfer Tank |
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Check Latest Price |
| RDS 71083 45-Gallon Rectangular Aluminum Tank |
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| Better Built 36-Gallon Steel Transfer Tank |
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Check Latest Price |
 RDS 71804 37-Gallon Auxiliary Fuel Tank |
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 RDS 60-Gallon Aluminum Fuel Tank |
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Check Latest Price |
 UWS TT-100-COMBO 100-Gallon Combo Tank and Toolbox |
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Check Latest Price |
 VEVOR 116-Gallon Portable Diesel Tank with 12V Pump |
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Check Latest Price |
 Dee Zee DZ92740B 43-Gallon Combo Tank and Toolbox |
|
Check Latest Price |
 Dee Zee DZ91752X 39-Gallon Narrow Aluminum Tank |
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Check Latest Price |
Three quick reads on that table. The steel tanks carry more capacity for the same footprint because steel does not need the wall thickness aluminum requires. The aluminum tanks weigh less empty and will not rust, which matters on a truck that sees road salt. The portable polyethylene unit is the odd one out: it is a complete pump-and-hose kit on forklift pockets, not a bed-mounted installation.
1. Dee Zee DZ92556NSB 42-Gallon Steel Transfer Tank – The Best All-Round Pick
Dee Zee DZ92556NSB Transfer Tank
14-gauge alloy steel
42 gallon capacity
70 pounds empty
59.5 by 19 inch footprint
Pros
- Heavy-gauge steel that takes abuse
- 5 stability baffles kill slosh and spread weld stress
- Mounting tabs included for bed securement
- Drain plug makes winterizing easy
Cons
- Large footprint needs careful bed measurement
- Some units arrive with light surface scratches
- Two-person lift recommended at 70 pounds
I keep coming back to the Dee Zee DZ92556NSB because it is the tank most people searching for the best transfer tanks for trucks end up with, and the reasons are boring in the best way. It is 14-gauge alloy steel, it holds 42 gallons, and it comes with mounting tabs and a drain plug. Nothing about it is exotic, and that is exactly why 185 owners have rated it 4.4 out of 5.
The five stability baffles are the detail that separates it from a plain box. Fuel moving inside a tank creates a load that works on every weld seam in a container, and baffles break that movement up. Dee Zee pairs them with radius curves that eliminate weld pressure points, so the tank does the same job as a straight-sided box without concentrating stress at the corners.
Owners also appreciate that the mounting tabs are part of the box, not an accessory. You can strap the tank down to bed anchors without drilling new holes, and the drain plug means you can empty it before winter storage without wrestling with a hose. The included hardware covers assembly and installation, which sounds minor until you are standing in a gravel driveway at 6 p.m. with no hardware store open.
The 59.5 by 19 inch footprint is the catch. It is one of the larger rectangles here, so measure the usable width of your bed between the wheel wells before you commit. At 70 pounds empty and around 282 pounds full of diesel, it is a two-person lift, and that is the complaint we saw most often. Several owners mentioned light surface scratches showing up on delivery, which is a handling issue rather than a manufacturing defect.
Check your bed width before ordering
This tank is wide and long, so it works best in a full-size or midsize bed with an open width of at least 20 inches between wheel wells. A compact truck with a narrowed bed will not clear it, no matter how the listing is worded. Measure the narrowest point and the length from the cab to the tailgate before the tank shows up.
The weight also matters for how you load it. Get a second person or a ramp, and lift it into place empty. Sliding a full steel tank across the bed rails is how people hurt their backs and put a dent in the tank at the same time.
Who should skip this tank
If you need a low profile that tucks under a tonneau cover, move on. This is a full-height rectangle, and the aluminum picks further down the list are shaped for exactly that reason. It is also the wrong choice if your payload rating is tight, since a full 42 gallons adds roughly 280 pounds to whatever else is in the bed.
Buyers who only plan to carry diesel and never gasoline will find the fuel_type listing worth a second look, because the listing marks this tank for gasoline use. Confirm the certification language against the label on your actual unit before you fill it with anything.
2. RDS 71083 45-Gallon Aluminum Tank – The Best Rust-Proof Per Gallon
RDS MFG INC 71083 Rectangular Auxiliary/Transfer Fuel Tank – 45 Gallon Capacity
Aluminum construction
45 gallon capacity
42 pounds empty
Fully welded seams
Pros
- Aluminum body will not rust
- Fully welded seams for leak resistance
- 45 gallons in a rectangle that fits most beds
- Large range of capacities across the RDS line
Cons
- Gasoline use requires siphoning from the top with an electric pump
- Install generally means cutting into the OEM fuel line
- Bed and frame clearance need measuring
The RDS 71083 carries the highest average rating in this roundup at 4.6 out of 5, with 82 percent of its 101 reviews at five stars. That score comes from a simple combination: an aluminum body that will not rust, fully welded seams, and 45 gallons packed into a rectangle most beds accept.
Aluminum is the material we recommend for anyone who lives where road salt is a fact of winter rather than a rumor. It will not rust the way a steel tank eventually will, and at 42 pounds empty it is light enough for one person to reposition in the bed. RDS builds this tank in a full range of capacities and dimensions, so if the 45-gallon version does not fit your bed, the same family usually has a near neighbor that does.
One detail in the listing matters a great deal and is easy to skim past. RDS states that gasoline auxiliary fueling is allowed only if the fuel is siphoned from the top of the tank using an electric pump. That is not a preference, it is a requirement tied to vapor pressure and static, and it means you cannot simply gravity feed gasoline out of this tank. Diesel is a different story and can move through a conventional line.
The second thing to plan for is the install. Owners of the RDS line consistently note that installation generally involves cutting into the OEM fuel line, which is a job for someone who has done it before unless your mechanic is eager. A cut line is a permanent change to the truck, and the fittings have to be sealed properly or you will have a fuel smell inside the cab within a month.
When aluminum is the right call
Choose this tank if your truck sees salt, mud, or coastal air, or if you plan to keep the truck for a decade or more. Aluminum will not develop the surface rust that makes a steel tank look tired, and it holds its value better for the same reason. It is also the lighter option, which matters when you are lifting a tank into a bed by yourself.
The 45-gallon figure is the sweet spot a lot of owners land on. It is enough capacity to roughly double the distance between fill-ups on a working truck without pushing a half-ton past its payload limit, and a full tank here is around 300 pounds of diesel.
Where owners run into trouble
The gasoline limitation is the biggest one. If your job involves refueling gas-powered equipment, this tank as listed will not do it with a gravity feed, and adding the electric top-siphon setup is part of the install rather than an afterthought. Budget for that hardware.
Second, the listing does not publish dimensions for this model, so you cannot check fit from the product page alone. Measure your bed width at the narrowest point and confirm clearance to the frame before ordering.
3. Better Built 36-Gallon Steel Tank – The Best Value Pick
Better Built Steel Transfer Fuel Tank – 36-Gallon, Rectangular, Black, Model Number 29211584
Alloy steel
36 gallon capacity
40 pounds empty
Overfill auto shutoff
Pros
- Most reviewed tank in the roundup at 305 ratings
- Overfill restriction shuts the pump off automatically
- Built-in baffles strengthen the shell and stop fuel shifting
- 2-inch flush bungs allow fast flow
- Lockable cap plus mounting kit included
Cons
- Some units arrive with a dented cap or bent mounting tabs
- Fitting a steel tank into a bed can take real work
- Full-tank weight is noticeable on lighter trucks
With 305 ratings, the Better Built 36-gallon steel tank is the most reviewed product in this entire roundup by a wide margin, and that gives you something the others cannot: a much larger sample of real installs to learn from. It scores 4.2 out of 5, with 66 percent at five stars.
The feature that wins buyers over is the overfill restriction. It provides automatic shutoff at the pump, so if you keep pumping past full, the flow stops rather than spraying diesel out of the filler. For anyone refueling equipment in the field, that is a safety and cleanup win, and it is the reason this tank is a better value than its specification list alone suggests.
Beyond the shutoff, you get built-in baffles that add structural strength and keep the contents from shifting during transport, 2-inch diameter flush-mounted inlet and outlet bungs for faster flow than a standard bung, and a lockable vented cap for security. The box also includes a mounting kit with rubber bushings, which saves you a trip for the hardware you would otherwise pick yourself.
It carries a 3-year warranty, which is the longest stated coverage among the steel tanks here. At 40 pounds empty, it is also the lightest of the three steel options in this list, and a 36-gallon tank is about 241 pounds full of diesel.
What the overfill restriction actually does
Think of it as a built-in stop. When the tank reaches its limit, the restriction shuts the pump down, so an overfilled tank does not end with a puddle of diesel on your equipment. This is the single most-praised feature in the reviews, and it is worth more than it sounds if you have ever had to mop up a spill at the end of a long day.
Pair it with a pump that has an automatic nozzle and the whole dispensing cycle becomes hands-off. You hook up the hose, open the nozzle, and walk away until the flow stops. That is the workflow a lot of owners say they wish every transfer tank supported.
Where the value pick falls short
Arrival damage is the most common complaint. Owners report dented caps and bent mounting tabs on units straight out of the box. Inspect the tank and hardware the day it arrives so you have an easy claim window, and file it before you install anything.
The other drawback is physical. Getting a steel tank into a bed is real work, and some owners ended up using a professional installer or making bed modifications. If your truck has a high bed rail, plan the lift before the tank is in your hands.
4. RDS 71804 37-Gallon Auxiliary Fuel Tank – Best for Pure Diesel Range
RDS MFG INC Auxiliary Fuel Tank 37Gal – 71804
Aluminum construction
37 gallon capacity
77 pounds empty
50 by 20 by 9 inches
Pros
- Aluminum body resists corrosion
- Vehicle-specific fit simplifies matching
- Multiple capacities available in the RDS range
- Gas fueling possible with a top siphon and electric pump
Cons
- Heaviest listed weight for its 37 gallon capacity
- Install is not beginner friendly
- 14 percent of reviews are 3-star
The RDS 71804 is the diesel-first option in this list. It is a 37-gallon aluminum auxiliary fuel tank listed for diesel, and its 4.1 rating across 123 reviews is the lowest average here, which is worth understanding rather than glossing over. Fourteen percent of those reviews sit at three stars, and the pattern behind them is consistent.
Owners credit the aluminum construction and the vehicle-specific fit, which takes some of the guesswork out of matching a tank to a truck. The RDS range covers multiple capacities, so the same platform often has a better-fitting sibling. What owners push back on is weight: at 77 pounds listed, this is the heaviest of the three aluminum tanks here relative to its capacity, and people consistently describe it as bulkier than they expected for 37 gallons.
That weight has a second-order effect people do not think about until the tank is installed. A taller, heavier tank sitting high in the bed pushes your center of gravity back and up, and for a truck that tows or carries a trailer, that changes the feel more than the spec sheet suggests. Measure the 9-inch height against your bed rail and your tonneau clearance before it goes in.
Installation difficulty is the other recurring theme. This is not a drop-in box with a filler cap and a hose port, and owners describe the process as truck-specific work rather than a weekend bolt-on.
Who this tank suits
It makes the most sense if your truck already has a specific fitment in mind and you want diesel range without any chance of rust. The vehicle-specific fit is the draw here: rather than measuring and hoping, the tank is designed around a particular truck. Confirm the fitment for your exact model before anything else.
Because the listing allows gasoline auxiliary fueling through a top siphon with an electric pump, the tank is not diesel-only, but diesel is the path of least resistance with this unit.
Where owners get frustrated
Expect a harder install than the photos suggest. Multiple reviewers point to the same pattern: the tank itself is fine, the installation is the part that takes time and occasionally a second trip to a hardware store.
The 14 percent three-star share is worth reading as a signal about expectations, not about quality. Owners who planned for a truck-specific install tend to rate it well. Owners who expected a weekend bolt-on tend to rate it low.
5. RDS 60-Gallon Aluminum Fuel Tank – Best for Long Diesel Runs
RDS MFG INC Fuel Tank – 60-Gallon
Aluminum body
60 gallon capacity
61 pounds empty
56 by 13 by 19.25 inches
Pros
- 60 gallons in a slim profile that fits under a tonneau cover
- Light enough for one person to reposition
- Baffles stop noticeable slosh
- Mounting kit with bolts and springs included
Cons
- Fuel gauge can read inaccurately
- Cannot transfer gasoline into another vehicle
- Filling past the full line pushes fuel out the relief valve
The RDS 60-gallon aluminum tank ties for the highest rating in the roundup at 4.6 out of 5, with 78 percent five-star across 80 reviews. What makes it interesting is the shape: 60 gallons compressed into a footprint that is only 13 inches wide at 56 by 13 by 19.25 inches overall, and that narrow profile is what lets it slide under a tonneau cover where a wider tank will not.
Owners love that the aluminum body stays light enough for one person to reposition in the bed, and the internal baffles kill the noticeable fuel slosh that makes a big tank feel unsafe in traffic. A mounting kit with bolts and springs is included, and at least one trucker reports it fitting a short-bed application with room to spare. The machined finish is a nice touch on a truck that sees weather.
The fuel gauge is the most-cited drawback and the one to know about. Owners report it reading inaccurately, sometimes sticking between the one-quarter and one-half marks, which means you should not trust it as your only way to know how much fuel is in the tank. If you need a real reading, budget for a separate gauge or learn to judge by the weight of the truck.
There is also a straightforward limitation in the listing: this tank cannot be used to transfer gasoline into another vehicle. Combined with the siphon-from-the-top rule that applies across the RDS gasoline-compatible models, that makes this a diesel tank first and foremost. It is a 60-gallon diesel range extender, not a gasoline dispenser.
Check your payload before you fill it
Sixty gallons of diesel is roughly 402 pounds, plus 61 pounds of empty tank, so you are adding about 463 pounds to the back of the truck. That is a real number against the payload figure on your door jamb, and it is the calculation most buyers in this niche get wrong.
Do the math before the tank arrives, not after. If your payload is already spoken for by a workbench, a trailer hitch, and passengers, the capacity has to come down, not the plan.
Who should look past this tank
If you refuel gasoline equipment, skip it. The listing is explicit that gasoline cannot be transferred into another vehicle from this tank, and that rules out a large slice of landscaping and small-engine work.
Also measure carefully. RDS states that this tank fits some short beds and advises measuring before ordering. The 19.25-inch height is the constraint for tonneau-covered beds, and the 56-inch length is the constraint for short beds.
6. UWS TT-100-COMBO 100-Gallon Tank and Toolbox – Best When You Still Need the Bed
UWS TT-100-COMBO 100 Gallon Combo Aluminum Transfer Tank
Aluminum combo unit
100 gallon capacity
160 pounds empty
60.5 by 31.5 by 24.5 inches
Pros
- 100 gallons and an integrated toolbox in one unit
- Fully welded one-piece tub absorbs dropped tools
- Foamed lid resists bending and warping
- Stainless steel paddle handle lock
Cons
- Not compatible with DEF fluid
- Heaviest unit here at 160 pounds empty
- 60.5 inch length limits which trucks fit
The UWS TT-100-COMBO answers the bed-space problem better than anything else on this list. It puts 100 gallons of diesel capacity and a locking toolbox in a single unit, so the bed stays usable for tools, gear and materials. For a contractor who has been choosing between carrying fuel and carrying a tool chest, that is the whole argument.
Build quality is the selling point in the details. The tub is fully welded as one piece, designed to absorb the impact of a dropped tool and prevent leakage. The lid is a patented fully foamed design that creates a rigid wall between the outer aluminum layers to resist bending and warping, and the offset hinge lets the lid open flat against a bed wall without rubbing. Security comes from a stainless steel paddle handle lock, and a commercial grade vented cap with mounting flanges handles ventilation for non-flammable liquids.
It is also the most polarized tank here. It rates 4.1 out of 5 from 70 reviews, with 69 percent five-star but 16 percent one-star, the widest spread in the group. The one-star reviews cluster around the same three things: the empty weight, the length, and what happens when the tank is not the right size for the truck.
At 160 pounds empty, this is the heaviest unit in the roundup before a single gallon goes in. Add roughly 670 pounds of diesel at full and you are looking at well over 800 pounds sitting behind the rear axle. That number decides the purchase for a lot of people, and for most of them the answer is no.
Who the combo format is for
This tank makes sense if you carry real tools and you have previously used a separate toolbox plus a tank, and found you did not have the bed space for both. The integrated layout is the most efficient use of a rectangular footprint we saw, and forum consensus has consistently pointed to combo units as the most recommended setup for people who still need their bed for gear.
It also suits anyone with a tonneau-covered bed who wants a secure, lockable storage solution alongside fuel. The lid doubles as a work surface and the lock keeps contents out of sight.
Where it falls apart
Measure twice, because the 60.5 by 31.5 by 24.5 inch footprint is large in two directions at once. It will not fit a short bed, and at 24.5 inches tall it will not go under most low-profile covers. Plan for a lift gate or three people when it arrives, and confirm you have a clear path from the tailgate to the mounting position.
One hard limitation: the unit is not compatible with DEF diesel exhaust fluid. If you are storing both diesel and DEF for a late-model truck, you will need a separate container for the DEF. The one-year warranty is also the shortest stated in this roundup.
7. VEVOR 116-Gallon Portable Diesel Tank – Best Complete Pump-and-Hose Kit
VEVOR Portable Diesel Tank, 116 Gallon, Black
Polyethylene body
116 gallon capacity
104.1 pounds empty
12V pump at 10.6 GPM
Pros
- Complete kit with 12V pump 13.1 foot hose and automatic nozzle
- 10.6 GPM flow rate for fast refueling
- Duplex filtration cleans diesel of coarse and fine particles
- UV resistant polyethylene will not corrode
- Lockable copper lid
Cons
- Not a bed-mounted installation the way steel and aluminum tanks are
- Polyethylene and pump assembly add weight at 104 pounds
- Diesel only
The VEVOR 116-gallon unit is a different product from the other eight, and the reason it makes the list is completeness. It ships as a working system: a 12V electric transfer pump rated at 140 watts, a 13.1 foot rubber hose, an automatic shutoff nozzle with a rotatable adapter, and a mechanical fuel gauge. You can fill a machine from it the day it arrives.
Flow rate is the number that matters here, and 10.6 GPM is fast. For comparison, moving that much fuel through a hand pump is a job most people try once and never again. The automatic nozzle shuts off when the receiving tank is full, and the rotatable adapter prevents the hose from knotting, which is a small detail that saves real time on every fill.
Filtration is the other differentiator. The duplex filter has an inner front-end element that separates large particles and an outer premium element that removes smaller impurities such as metal and colloids. For anyone filling modern diesel equipment with tight injectors, that is worth more than it sounds, and it is not something the bed-mounted tanks in this roundup offer.
The body is 6mm polyethylene, reaching 12mm at the thickest part, and it resists UV radiation and changing weather conditions without the corrosion profile of steel. The upper lid locks with a copper lock, and the transport grooves plus integrated forklift pocket are for moving 104 pounds around with equipment rather than by hand.
Why owners rate it 4.4 out of 5
It holds a 4.4 across 179 reviews with 76 percent five-star, and it ranks fifth in the Fuel Transfer Tanks category. The reason is simple: everything you need is in the box. Owners consistently point out that they did not have to source a pump, hose, nozzle, or fittings separately, which is the most common complaint about assembly-kit tanks in this niche.
The filter and the automatic shutoff are the two features reviewers single out most, along with how fast the pump moves fuel.
Where it is the wrong tool
It is a portable unit, not a bed-mounted installation. The mounting hardware is designed for transport and forklift handling, and none of the bed tabs, brackets or tie-down points you would want for a truck bed are part of this package. If you need a tank that lives in the bed, this is not it.
It is diesel only, and at 104.1 pounds empty the polyethylene body plus pump assembly is heavier than several steel tanks in this list. Nine percent of reviews are one-star, which is worth reading as a signal that the expectations gap is mostly about what kind of product this is.
8. Dee Zee DZ92740B 43-Gallon Combo Tank – Best Compact Two-in-One
Dee Zee DZ92740B (43 gallon) Black Aluminum Combo Transfer Tank & Tool Box
Black aluminum
43 gallon capacity
50 pounds empty
21.33 by 18 inch tank body
Pros
- Combines 43 gallons of fuel with toolbox storage
- Black aluminum body is lighter than steel and rust proof
- Compact 18 inch height fits under many tonneau covers
Cons
- Smallest review base in this roundup at 45 ratings
- 89 pounds in the package so unloading takes help
- Sparse specification data versus the Dee Zee steel models
The Dee Zee DZ92740B is the compact take on the combo format. It combines 43 gallons of fuel capacity with an integrated toolbox, and at 18 inches tall the tank body clears many tonneau covers where the larger UWS combo does not. That height difference is the single reason to consider this model over a 100-gallon combo.
The black aluminum body is the second argument. Aluminum is lighter than steel, so a 50-pound empty tank is far easier to position than the 89-pound package weight implies once it is out of the box, and it will not develop surface rust on a truck that lives outside. The toolbox is what makes it practical day to day: your bed stays organized instead of becoming a fuel tank with a pile of tools around it.
What you give up is certainty. With 45 ratings this is the smallest review base in the roundup, and the listing carries less specification detail than the Dee Zee steel models, including no stated fuel type or warranty. The 4.1 rating with 58 percent five-star is respectable but thin evidence, and thin evidence is exactly what a buyer should weigh when the purchase is this large.
Measure before you order. The package dimensions are listed at 56.69 by 21.33 by 18.89 inches, and the tank body at 21.33 by 18 inches, but there is no fitment guidance in the listing, so the bed measurement is on you.
Where this combo design wins
The toolbox-plus-tank layout is the most commonly recommended setup in owner discussions for people who still need their bed for tools or gear, and this model does it in a smaller envelope than most. The 18-inch height is the number to check first, because it is what determines whether a tonneau cover clears.
For a service truck, a mobile mechanic, or a contractor running a single machine, 43 gallons is a meaningful amount of fuel that does not swallow the whole bed.
Where it falls short
The package weight of 89 pounds is the practical problem. That is two people and a slow lift, and if you are installing it yourself in a driveway, plan the move before the box is opened. Owners in this category consistently warn about underestimating that step.
Beyond the weight, the listing is thin on details you would want before buying: no fuel type, no stated warranty period, and no fitment information. Ask the seller for the certification label photo and the actual tank dimensions before you commit.
9. Dee Zee DZ91752X 39-Gallon Narrow Aluminum Tank – Best for a Tight Bed
Dee Zee DZ91752X (39 gallon) Narrow Auxiliary Diesel Fuel Transfer Tank
DOT certified aluminum
39 gallon capacity
12 pounds empty
Pressure tested to 29 psi
Pros
- DOT certified and hydrostatically pressure tested to 29 psi
- Narrow profile fits in front of a toolbox and under a cover
- 0.125 inch Brite-Tread aluminum will not rust
Cons
- Some users report a slow fuel transfer rate
- Install is truck-specific and can mean cutting a cargo anchor
The Dee Zee DZ91752X is the narrowest tank in the roundup at 12 pounds listed weight and a profile slim enough to sit in front of a toolbox or tuck under a cover. At 39 gallons it is a diesel range extender, and the listing states it is a certified auxiliary fuel transfer tank that meets federal DOT requirements.
It is also the one tank here with an explicit pressure test figure. The tank is hydrostatically pressure tested to 29 psi, which is a concrete number you can compare against other listings instead of taking a vague certification claim on faith. The body is 0.125 inch Brite-Tread aluminum with a vented cap, full weld stability baffles and a drain plug, and it is compatible with center-mounted transfer pumps.
Owners report meaningfully extended range from a 39-gallon tank, and the narrow shape is what makes that possible in a bed they also use for work. One of the strongest signals in the reviews came from a warranty replacement: Dee Zee honored a lifetime limited warranty replacement when a unit cracked, which is the kind of service story that tells you more about a brand than a spec sheet does.
How to verify the DOT certification yourself
Ask the seller for a clear photo of the certification plate on the tank before you buy, and check that the model on the plate matches the model being shipped. DOT-certified units carry markings covering the tested capacity and the test standard, and a seller who cannot produce that plate has not done their homework.
Note that gasoline approvals can carry a retest interval, sometimes as short as two and a half years, and that a periodic re-test requirement applies to certain fuel service tanks. This tank is listed for diesel, so confirm the fuel type on the plate matches what you plan to put in it.
Where owners run into problems
The most common complaint is a slow fuel transfer rate reported by some users, which is often a pump or line-size issue rather than the tank itself. The second is the shut-off valve design, which requires an added 90-degree fitting in some trucks before the connection works.
Installation here is truck-specific. Owners mention bed modifications such as cutting a cargo anchor, and factory plastic bed liners that have to be cut away around the valve area. Plan for an afternoon and a set of quality tools, or pay a shop to do it. The stated warranty on this listing is 30 days, which is the shortest in the roundup, so get the install inspected before that window closes.
Transfer Tank vs Auxiliary Fuel Tank: What the Rules Actually Say
A transfer tank dispenses fuel to other equipment. An auxiliary fuel tank feeds your own engine. That one sentence decides the legal question, and almost every bad purchase in this niche comes from a buyer who thought the two were the same thing.
A transfer tank sits in the bed, runs a pump, and sends fuel through a hose to a generator or a tractor. It is a cargo container, and it is regulated as one. An auxiliary tank is plumbed into the truck’s fuel system so the engine draws from it, and that is a different regulatory category with a much harder compliance bar.
Federal rules on fuel tanks carried in commercial motor vehicles live in 49 CFR 393.65, and the requirements around discharge and connection are specific. Gasoline cannot be gravity fed out of a tank; it has to be pumped from one tank to the other through the top of the tank, because of vapor pressure and static. That requirement shows up repeatedly in the manufacturer listings in this roundup, and it is the reason several of these tanks are specified for diesel first.
On the auxiliary side, NHTSA has issued an interpretation, nht79-3.8, that discourages auxiliary fuel tanks because of the fire and explosion risk they create in a collision. Owners worry about this for good reason, and it is why we built this roundup around transfer tanks rather than range-extending auxiliary systems. If your goal is to refuel your own truck from a bed tank, understand that you are in a different and less comfortable regulatory conversation than the one covered here.
On hazmat: how much fuel you may haul without an endorsement depends on the commodity and the quantity, and the thresholds are set by the Department of Transportation rather than by the tank brand. If you are moving fuel as part of a business, read the rule for your specific fuel and quantity instead of relying on a forum answer.
How to Choose a Transfer Tank for Your Truck
Choose by use case first, capacity second, and shape third. Most buyers get this backwards, buy the biggest tank that fits, and end up over their payload rating with an unusable bed. Work through these six criteria in order and the decision makes itself.
1. Start with the job. A mobile mechanic refueling a single compressor needs 40 gallons. A contractor running a fleet of machines on a remote site needs 100. A portable tank that moves between trucks needs no bed space at all. Write down how much fuel you move per week and how far you drive, then size from that number rather than from the largest tank in the category.
2. Do the payload math. Fuel weighs about 6.7 pounds per gallon. A 100-gallon tank is roughly 670 pounds of fuel plus 160 pounds of hardware, and that figure goes straight against the payload number on your door jamb. A 60-gallon tank adds around 400 pounds. Most half-ton trucks have somewhere between 1,000 and 2,000 pounds of payload, and your passengers, hitch, and work gear are already spending it.
3. Measure the bed three ways. Width at the narrowest point between the wheel wells, length from the cab to the tailgate with the tailgate closed, and height from the bed floor to the top of your tonneau cover. The third measurement eliminates more combo tanks than people expect, because a 24.5-inch tank will not clear a low-profile cover and an 18-inch one usually will.
4. Match material to your climate and your hands. Aluminum will not rust and is lighter to lift, which makes it the right pick for salt-belt trucks and anyone installing alone. Steel holds more capacity for the same footprint because the walls can be thinner, and it takes abuse better. Polyethylene will not corrode at all but is a portable format rather than a bed-mounted one.
5. Decide how fuel leaves the tank. A hand pump is cheap and reliable but slow. A 12V electric pump with an automatic shutoff nozzle is faster and hands-off, and some tanks such as the VEVOR unit include the pump, hose and nozzle in the box. Confirm whether gasoline is permitted in the model you are buying, and confirm whether it must be siphoned from the top with a pump rather than gravity fed.
6. Read the compliance language, not the marketing. A listing that says DOT certified, EPA specification, or states a hydrostatic test pressure is telling you something verifiable. A listing that says heavy duty and nothing else is telling you nothing. Ask for a photo of the certification plate on the actual unit before money changes hands.
On capacity tiers, the market is consistent: 25 to 40 gallons for a single machine or a service van, 50 to 60 gallons for a contractor working a fixed site, 75 to 100 gallons for a fleet or a generator-heavy job, and above 100 gallons for people who have genuinely done the payload math. The RDS 60-gallon tank and the UWS 100-gallon combo sit at the top of the practical range for pickups; beyond that you are usually looking at a dually or a service body.
On shape, there are three options. A standard rectangle gives you the most capacity per dollar. An L-shape or wedge unit trades some capacity for bed space along one wall, which matters if you still load pallets or materials. A combo tank and toolbox unit gives up nothing in storage and wins back the bed space that a standalone box consumes, which is why it is the most recommended format among owners.
If you are still narrowing the field after capacity, our separate guides on fleet fuel transfer tanks and fuel transfer pumps go deeper on the dispensing side. For equipment that is not diesel, our generator transfer switch guide covers the other half of a mobile power setup.
Installation, Securement and Winterizing
Mount the tank empty, in daylight, with the bed fully empty. That last part is not optional. A 100-gallon combo is 160 pounds of awkward aluminum with no handholds, and loading it over a loaded bed is how tanks get dropped and how people get hurt.
Secure it to the bed, not to the tailgate. Use the mounting tabs and the included kit, and run straps to bed anchors or to properly rated tie-down points. The Dee Zee and Better Built units both ship with mounting hardware for exactly this. Ratchet straps alone are not a mounting system; they are a restraint for something that is already bolted down.
Route the vent outside the cab. The vented filler cap on these tanks is there so the tank can breathe as fuel moves. Make sure the vent path is not blocked by a tonneau cover, a headache rack, or a bed liner cut too tight, and check it periodically for debris and spider webs, which is a complaint that shows up over and over in owner threads.
Ground the pump. If you are installing a 12V transfer pump, run the power from the truck with an in-line fuse, and bond the pump housing to a clean ground point on the truck frame. Unfused pump wiring is the leading cause of a dead pump, and an unbonded housing is a static problem when you are moving gasoline.
Plan the discharge side. For diesel, most owners use a conventional line into the filler. For gasoline, remember that it must be pumped from the top of the tank rather than gravity fed, and that the RDS models listed here specify an electric pump for gasoline fueling. Get this right before you fill the tank, not after.
Drain it before it sits. Every tank in this roundup with a drain plug is drainable for a reason. Water condenses in diesel, it settles to the bottom, and it will destroy injectors on the equipment you are refueling. The Better Built and Dee Zee units both have drain plugs; use them at the end of the season and run the tank dry.
If you are building a mobile power setup rather than a fuel delivery rig, our guide to fluid transfer pumps covers the pump side in more detail, and the gear oil pump roundup is worth a look if you carry lubricants alongside fuel.
Frequently Asked Questions
Who makes the best diesel transfer tank?
For most truck buyers, Dee Zee builds the best all-around diesel transfer tank, with 14-gauge steel, five stability baffles, mounting tabs and a 4.4 rating across 185 reviews. If you want an aluminum body that will not rust, the RDS 60-gallon tank rates highest at 4.6 with 80 reviews and a narrow profile that fits a short bed.
What is the difference between a transfer tank and an auxiliary fuel tank?
A transfer tank dispenses fuel to other equipment through a pump, hose and nozzle, and is regulated as cargo. An auxiliary fuel tank is plumbed into your truck’s own fuel system so the engine draws from it, which falls under stricter crash and fire rules and has drawn NHTSA discouragement in interpretation nht79-3.8.
Are transfer tanks DOT approved?
Look for a certification plate on the tank itself listing the tested capacity and the applicable standard. A hydrostatic test pressure quoted in the listing is a good sign of real compliance, and you can compare it between models. Gasoline approvals on some tanks carry a periodic re-test interval, sometimes as short as two and a half years.
How much does a transfer tank weigh when full?
Fuel weighs about 6.7 pounds per gallon, so add roughly 6.7 pounds for every gallon of capacity plus the empty weight of the tank. A 100-gallon tank with 160 pounds of hardware comes to about 830 pounds loaded, and a 60-gallon aluminum tank lands near 463 pounds. Check both against the payload rating on your door jamb.
How to choose the right transfer tank?
Work through six criteria in order: define the job and how much fuel you move weekly, run the payload math, measure bed width, length and tonneau clearance, match material to your climate, decide between a hand pump and a 12V pump with automatic shutoff, and read the compliance language on the listing before you buy.
Can you put gasoline in a diesel transfer tank?
Only if the manufacturer says so. Several tanks in this roundup are listed for gasoline but require that fuel be siphoned from the top of the tank with an electric pump rather than gravity fed, because of vapor pressure and static. The RDS 60-gallon model is the opposite case: it cannot be used to transfer gasoline into another vehicle at all.
Final Verdict: Which Transfer Tank Should You Buy
The best transfer tanks for trucks in 2026 come down to three honest decisions. If you want one tank that works for most contractors with no fuss, buy the Dee Zee DZ92556NSB: heavy-gauge steel, five baffles, mounting tabs in the box, and the most review history supporting it. If you would rather have aluminum that will not rust and a shape that fits a tight bed, the RDS 60-gallon tank is the highest-rated option here and slips under a tonneau cover.
If you carry tools as well as fuel, the combo format is the move, and the choice is between the compact Dee Zee DZ92740B at 18 inches tall and the UWS TT-100-COMBO if 100 gallons and a full locking toolbox justify the 160-pound empty weight and the payload hit. If you are not mounting anything and just need a working pump, hose and nozzle on a diesel job, the VEVOR 116-gallon kit is ready the day it arrives.
Before any of them, do two things: check the payload number on your door jamb against a full tank, and measure your bed width, length and tonneau height. Those two checks eliminate more wrong purchases than any spec sheet will save you time.