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The real reason truck owners add a bed fuel cell isn’t horsepower — it’s the freedom to skip the overpriced station on the interstate and fuel up where diesel is actually cheap. It’s also about avoiding the stress of hunting for a fuel stop when towing a fifth wheel or tractor. But these tanks vary widely in capacity, material, and bed fit, so choosing blindly can lead to costly mistakes.
I’m Mo Maruf — the founder and writer behind GoCarLife. This guide is built by comparing the manufacturers’ published specifications and the patterns across verified customer reviews, so you get each pick’s real strengths and trade-offs instead of marketing spin.
You want more range without giving up your whole truck bed, so here is a clear look at the best truck bed fuel cell options that balance capacity, build quality, and the realities of a weekend install.
Our Picks at a Glance



How To Choose The Best Truck Bed Fuel Cell
Match the tank to your fuel type, bed dimensions, and transfer method before purchasing.
Match the Tank to Your Fuel
Diesel tanks can also hold gasoline in some cases, but not always. The Better Built and Dee Zee aluminum units are diesel-specific, while the RDS 71083 is explicitly for gasoline. Always verify the fuel type in the specs, as using a diesel tank for gas (or vice versa) can be a serious mistake.
Aluminum vs. Steel vs. Plastic
Aluminum tanks like the RDS and Dee Zee options resist rust entirely, a top reason owners choose them. Steel tanks are heavier and cheaper but risk corrosion. Polyethylene (PE) and LLDPE tanks, like the VEVOR and FMCNMech, are lightweight, dent-resistant, and UV-stable, making them ideal for farms and job sites.
Check Height for Your Tonneau Cover
If you run a bed cover, tank height matters. The Dee Zee DZ92556NSB sits below the bed rails, so you can seal it up. The RDS 71083, however, sits slightly above the rails, which means a hard tonneau won’t close. Measure your bed’s side rail height and compare it to the tank’s dimensions before ordering.
Quick Comparison
| Model | Best For | Material | Fuel Type | Weight | Amazon |
|---|---|---|---|---|---|
| RDS 71083 (45 Gal)★ Best Overall | Long-haul gas range | Aluminum | Gasoline | 42 lbs | Amazon |
| Dexepe Universal (20 Gal)Classic Build Pick | Hot rods & classic pickups | Aluminum | Gasoline | 11.82 kg | Amazon |
| FMCNMech (32 Gal)Farm Favorite | Farm equipment refueling | LLDPE | Diesel | — | Amazon |
| Better Built (36 Gal) | Diesel equipment on a budget | Alloy Steel | Diesel | 40 lbs | Amazon |
| BreAro (58 Gal) | High-capacity diesel transfer | HDPE | Diesel | — | Amazon |
| VEVOR (48 Gal) | Dual fuel (diesel & gas) | Polyethylene | Diesel, Gasoline | 55.6 lbs | Amazon |
| Dee Zee DZ92556NSB (42 Gal) | Tonneau cover compatibility | Alloy Steel | Gasoline | 70 lbs | Amazon |
| RDS 71783 Wedge (63 Gal) | Maximum fifth-wheel range | Aluminum | Diesel | 61 lbs | Amazon |
| Dee Zee DZ91753 (110 Gal) | Bulk fuel storage & savings | Aluminum | Diesel | 100 lbs | Amazon |
| TITAN 5410050 (50 Gal) | Complete factory-style system | Plastic | Diesel | 68 lbs | Amazon |
In-Depth Reviews
1. RDS MFG INC 71083 Rectangular Auxiliary Fuel Tank
Our pick — over 4.5★ from 100+ verified ratings; the strongest balance of quality and price.
The aluminum workhorse that adds serious range without the rust worry.
If you drive a Ram 2500 or 3500 and want to stop guessing where the next cheap gas station is, this 45-gallon aluminum tank is the crowd favorite for a reason. The fully welded seams and rust-free aluminum construction mean it shrugs off weather that would start eating a steel tank, and the billet fill cap adds a premium touch you notice every time you fuel up.
You can add 45 gallons of fuel capacity in under two hours on a 2016 Ram 3500, according to owners — fast for a job this size. The tank sits slightly above the bed rails, so it won’t work if you need a hard tonneau cover to close flat; but with a fifth wheel or an open bed, that clearance is a non-issue. The value is strong: at 45 gallons versus 20 gallons, you get more than double the capacity of the Universal option, giving you a massive range advantage for a modest step up in complexity.
Buyers report it works well as both an auxiliary and a transfer tank, saving money by letting you skip high-price stations. The main caveat is the shipping box — a few units arrive with bent mounting brackets that need a bit of hammer work, which is frustrating even if the tank itself is in great shape.
What Wins Owners Over
- Easy installation — consistently done in under two hours
- Aluminum means no rust, ever
- Huge 45-gallon capacity for long hauls
What to Watch For
- Sits above bed rails, so a tonneau cover won’t close
- Shipping can bend mounting brackets
Your best bet if: you haul a fifth wheel or tow long distances and want a proven, rust-free aluminum tank that installs quickly.
Think twice if: you need a cover to seal the bed flat — the tank’s height gets in the way.
2. Universal 20 Gallon 80L Fuel Cell Polished Aluminum
Polished show quality that belongs in a classic pickup, not just a work rig.
For a Model A pickup or a derby car, looks matter as much as function, and this 20-gallon tank delivers both. The polished aluminum exterior is easy to clean, and the size tucks neatly into a wood box in the bed without dominating the space — owners mention it’s “just the right size” for that kind of classic build.
Inside, anti-sloshing foam keeps fuel supply level even when you’re hard on the throttle, which is a safety net for track cars and street racers that the big rectangular tanks don’t offer. It also comes as a complete kit: dual 10 outlets, dual 10 vent outlets, a 12-foot nylon braided 6AN fuel line, and all the 90-degree, 45-degree, and straight 6AN adapters you need. You will not be hunting for extra fittings.
At 20 gallons, it’s the entry point in this list — a 2.2x smaller capacity than the RDS 45-gallon option — so it’s not built for long-haul range. It’s built for a cool project that needs a dependable, good-looking fuel source. Owners say it works great with no issues, though some note they would not trust it completely at a full fill.
Project perfect: this universal cell suits classic pickups, hot rods, and race builds where polished looks and a complete adapter kit matter more than raw capacity.
3. FMCNMech 32 Gallon Diesel Transfer Tank with Pump
A wheeled caddy that brings diesel to the tractor, not the other way around.
This one breaks the mold because it is not designed to stay bolted in your bed — rugged all-terrain wheels and a sturdy handle let you roll 32 gallons of diesel right up to the tractor or job-site equipment. The linear low-density polyethylene (LLDPE) construction resists corrosion, impact, and UV exposure, which matters when it lives outdoors on a farm.
The 12V electric pump delivers up to 10 GPM, and the 13-foot hose gives you plenty of reach so you don’t have to pull the tractor all the way into the garage to refuel. An auto shut-off nozzle and anti-leak fittings keep the transfer clean and spill-free, and owners confirm plenty of transfer power with the nozzle cutting off as advertised.
The recurring caution is the vented filler cap — customers note it does not vent enough air while pumping, which can collapse the tank and crack it. This is a real risk with this design, so plan on upgrading or modifying the breather valve before heavy use.
Mobility Wins
- All-terrain wheels make it truly portable
- 10 GPM pump with a 13-foot hose reaches far
- LLDPE shrugs off impacts and UV
The Trade-Off
- Vented cap can collapse the tank while pumping
- Not a permanent bed mount like others here
Reach for this if: you need to move diesel to scattered equipment on a farm or job site without dragging machines to the tank.
Look elsewhere if: you want a fixed bed installation — this is a portable caddy first.
4. Better Built Steel Transfer Fuel Tank – 36 Gallon
A bolt-on steel tank that is compact enough to save real bed space.
For a diesel equipment owner on a budget, the Better Built 36-gallon tank delivers a lot without taking up the whole bed. It is a compact 11 inches wide and 17 inches tall, so it bolts on easily and leaves room for the rest of your gear. The built-in baffles add strength and stop the contents from sloshing around as you drive, which keeps the tank stable and the handling predictable.
The overfill restriction gives you an automatic shutoff at the pump to prevent spills, and the 2-inch diameter flush-mounted inlet and outlet bungs allow fast flow when you are filling or dispensing. A lockable cap adds security, which matters when you are parked on a job site overnight. Owners describe it as very well built and durable, fitting nicely on a black flatbed.
Two honest cautions: it is a diesel-only tank, so do not put gasoline in it, and the shipping packaging is famously bad — several units arrive with bent mounting tabs and dents that need straightening. The tank itself is solid, but the journey to your door can be rough.
Compact and capable: this steel tank earns its keep for diesel equipment users who want a low-cost, space-saving transfer solution and can tolerate minor shipping dings.
5. Fuel Transfer Tank, 58 Gallon for Diesel with 12V Pump
A high-density plastic giant that refuels tractors and generators with ease.
When you are tired of juggling five-gallon cans for the tractors and generators, this 58-gallon HDPE (high-density polyethylene) tank makes the case for going big. The transfer pump pushes up to 10.6 GPM, which means refueling a Kubota MX tractor is quick, and a built-in filter keeps the diesel clean as it flows. The battery cable stretches 13.1 feet so you can reach the pump from a variety of positions.
The integrated forklift pocket design is a standout — it lets you lift the tank onto your truck safely even when full, which is a real safety win compared to wrestling a heavy tank by hand. A fuel level indicator lets you monitor inventory at a glance, and the auto shut-off nozzle stops the flow when the vehicle tank is full to prevent waste.
The honest catch is capacity accuracy. It is advertised as 58 gallons, but reviewers point out it actually only takes about 52 gallons due to the recessed pump and inlet design. That is still a huge amount of fuel for the farm, just not quite the full advertised number. The lid is also noted as feeling less sturdy than the rest of the build.
Big-Rig Benefits
- Forklift pockets make full-tank lifting safe
- 10.6 GPM pump with a 13.1-foot battery cable
- Built-in filter keeps fuel clean
Reality Check
- Actual usable capacity is around 52 gallons, not 58
- Water can pool under the cover in weather
Grab this for: a farm or construction site where you need high-volume diesel transfer and appreciate forklift-safe handling.
skip it if: the exact advertised gallon count matters more than the convenience of the pump and safety pockets.
6. VEVOR Portable Diesel & Gasoline Tank, 48 Gallon
One rugged tank that handles both diesel and gasoline for total fleet flexibility.
This red 48-gallon VEVOR stands out because it handles both diesel and gasoline, making it the one tank that covers trucks, tractors, ships, and RVs. The high-quality polyethylene construction resists UV radiation and handles changing weather, so it can live in the bed or on the job site year-round. A copper lock on the upper lid guards against theft.
The 12V transfer pump moves fuel at 10.6 GPM, and the duplex filter system is a real upgrade — the front-end filter catches large particles while a premium outer filter traps small stuff like metal and tiny particles. That is the kind of protection that keeps your equipment’s fuel system clean. The mechanical fuel gauge lets you monitor capacity so you know when to refill.
Owners who use it for home heating oil hauling love it, and one reports their first unit lasted three years flawlessly before they bought a second. The grooved sides and forklift pockets keep it secure in the bed. Just know that straightening out the capacity claims can be confusing in reviews, and the pump cables may be too short to reach your battery directly on some trucks.
One tank, many fuels: the VEVOR is the flexible pick for mixed fleets, with a dual-filter system that protects diesel and gasoline engines alike.
7. Dee Zee DZ92556NSB Transfer Tank
The steel tank that hides under your bed rails so a tonneau cover still works.
If you tow a fifth wheel through the mountains of Colorado, this 42-gallon Dee Zee is built for exactly that. The heavy-duty 14-gauge steel construction and 5 stability baffles keep everything solid at highway speeds, and the radius curve design eliminates weld pressure points that cause cracks. The mounting tabs secure it straight to the truck bed.
The killer feature is the height. It fits under the bed rails, so a bed cover can still be used — owners running it as an auxiliary tank confirm the cover seals over it. One buyer on a 2021 Ram 3500 dually reports it sits below the bed side rail, with only the cap poking up a bit. Combined with the factory tank, it gives a total of 67 gallons of range for those long trips.
Because it sits so low, a pump will stick above the bed if you use it as a transfer tank, but as a filler for your main tank it stays neatly concealed. It installs fairly quickly with good instructions and has shown no leaking over time. The trade-off is the same as every steel tank here: shipping can arrive with bent tabs, so inspect before you mount.
Low Profile Advantage
- Sits below bed rails for tonneau cover use
- 14-gauge steel with 5 stability baffles
- Raises range to 67 gallons total on many trucks
Watch It
- Steel is rust-prone in salt-belt climates
- Bent mounting tabs on arrival in some cases
Perfect for: fifth-wheel towers who want a concealed tank that keeps the bed cover usable and adds significant mountain range.
Not for you if: you live in a heavy-salt area where you would prefer aluminum’s rust immunity.
8. RDS MFG INC 71783 Auxiliary Fuel Tank 63Gal Wedge
A 63-gallon wedge of aluminum that lets you pick your fuel price, not your fuel stop.
For the serious long-hauler, this RDS wedge tank is the premium choice that transforms a truck into a cross-country machine. Built from single-sheet aluminum with welded top and sides, it adds a massive 63 gallons to your range. One owner with a Ram 3500 reports the install takes about three hours solo, and the tank top sits flush with the bed rails — only the filler cap and vent stick up about 2.5 inches.
The wedge shape is the smart detail here. It is about 4 inches narrower than a custom rectangular tank, which helps it avoid bracket weld failures and keeps the load balanced. It comes with spring bolts and a rubber strip to absorb movement, so you do not bolt it directly to the frame — a safety consideration for crash protection. Owners say it is invisible from the driver’s seat, making it ideal for fifth-wheel hitching where you need the bed clear.
Shoppers say it as the “best addition to my truck period,” loving that they can pick their fuel price out west instead of hunting for the next station. The locking cap comes with two keys for security. It is a diesel-only tank that adds roughly 1,000 miles of potential range for many setups, though the value for money gets mixed reviews compared to the more budget-friendly options.
Range royalty: this wedge delivers the biggest single-tank range jump on the list with a flush fit that keeps your bed usable — the premium price buys you real capability.
9. Dee Zee DZ91753 (110 Gallon) Rectangle Transfer Tank
A 110-gallon aluminum monster that pays for itself hauling bulk diesel.
This is the tank for farmers and fleet owners who buy diesel in bulk to save money. The 110-gallon capacity is the biggest on this list, and at 100 pounds when empty it is still light enough for a 120-pound person to move around. The 0.125 brite-tread aluminum construction is non-rusting, and the radius curve design eliminates weld pressure points, so it holds up outdoors for years.
Buyers report using it for 7 years of outdoor use with zero leaks, hauling bulk fuel and saving serious money. When you add a transfer pump and buy diesel in quantity, it genuinely pays for itself multiple times over. The rectangle shape — 48 inches long by 24 inches wide by 24 inches high — fits most full-size truck beds, and the mounting tabs secure it directly to the bed.
One legal note buyers flag: the label states it is not for gravity feeding into a vehicle fuel tank, and it is not approved for gas transfer. It is designed for pumping into equipment via an overhead pump. Also, the aluminum can have sharp burrs inside the screw cap and fittings, so wear gloves when you handle it.
The Bulk Advantage
- 110 gallons of storage slash refueling trips
- Non-rusting aluminum survives years outdoors
- Pays for itself hauling bulk diesel
Know the Limits
- Not for gravity feeding vehicle tanks
- Sharp aluminum burrs inside fittings
Your move if: you buy diesel in bulk and want the maximum storage capacity that will pay for itself in fuel savings.
Hold off if: you need to gravity-feed your truck’s tank directly — this one is for overhead pumping into equipment.
10. TITAN Fuel Tanks 5410050 50 GAL Fuel System
A factory-style system that fits under the tonneau and includes everything for install.
This TITAN 50-gallon system is for the truck owner who wants a matched, vehicle-specific kit rather than a universal tank. It is designed to fit perfectly in the truck bed — one owner installed it in a 2023 F350 pulling a fifth wheel and called it “absolutely awesome,” noting it includes everything you need to install. The plastic construction is solid and fits neatly under a tonneau cover.
For tower families, the value is real: owners mention saving to per gallon by filling up with cheaper bulk fuel, with a payback in about two years. The built-in fuel pump makes transferring fuel to the main tank easy, and the controls are straightforward. It fits under the tonneau securely, keeping the bed usable and the tank protected.
The install is the catch — it is tedious at around 4 hours, and the template can mislead if you do not align it with the bed top rail correctly. The included pump is also on the weaker side per some owners, and a few note the vent adapter lacks barbs and a locking cap costs extra. But the quality is high, and the manufacturer replaced a failed fuel pump under warranty quickly for one owner.
System Perks
- Vehicle-specific fit that drops under a tonneau
- Includes pump and all install hardware
- Saves real money on bulk fuel, pays off in ~2 years
Install Realities
- 4-hour install with a finicky template
- Included pump is weaker than aftermarket options
Choose this for: a clean, covered-bed install on a late-model truck where you want a matched system with everything in the box.
Consider another if: you dislike long installs or want a stronger transfer pump right out of the gate.
Understanding the Specs
Material: Aluminum vs. Steel vs. Plastic
Aluminum is the rust-free darling — it never corrodes, so it is ideal for trucks that live outdoors or in wet climates. Steel is cheaper and heavy-duty but will rust over time, especially in salt-belt winters. Polyethylene (PE, HDPE, LLDPE) is lightweight, dent-resistant, and shrugs off impacts and UV, making it the go-to for portable caddies that get rolled around farms and job sites.
Capacity and Range
Gallons translate directly to miles. A 45-gallon tank like the RDS 71083 adds roughly double the range of a 20-gallon universal cell for a typical truck. Think about your daily round trip and how often you want to stop for fuel — bigger is better for fifth-wheel towers, while 20-32 gallons suits local equipment refueling.
FAQ
Can I install a truck bed fuel cell myself?
Will a fuel cell fit under my tonneau cover?
Can I use a diesel tank for gasoline?
Why does my tank need proper venting?
What is the difference between an auxiliary tank and a transfer tank?
How much weight does a full fuel cell add to my truck?
Is a 20-gallon fuel cell big enough for a classic truck?
What happens if my tank gets a small leak?
Do I need a separate pump for an auxiliary tank?
Are steel tanks safe from rust over time?
Final Thoughts: The Verdict
For most people, the truck bed fuel cell winner is the RDS 71083 because it delivers a massive 45-gallon aluminum tank that installs in under two hours and never rusts. If you want a classic look for a project build, the Universal 20-gallon polished cell is the crowd-pleaser. And for a farm or job site where you need diesel on wheels, the FMCNMech 32-gallon caddy brings the fuel to the equipment.
How We Picked
We do not accept paid placement. Every pick is matched to a real buyer and a real use-case; we do not hands-on test units.
Sources & Methodology
Specifications: manufacturer listings and product documentation. Review insights: verified customer reviews, as of August 2026. Pricing: not shown on this page (it changes often); check the current price via the retailer link.
As an Amazon Associate, GoCarLife earns from qualifying purchases. This does not affect which products we feature.







