AM-TANK 58 Diesel Portable Tank - 58 Gallon, Fits Under Truck Tonneau Cover, 12V Pump, Particulate and Water Filter, 13ft Hose, Auto-Nozzle

Why I chose this 58-gallon diesel tank

I needed a portable way to move and dispense diesel without giving up my entire truck bed or removing my tonneau cover. The 58-gallon AM-TANK fit that brief: low-profile enough to ride under a cover, integrated 12V pump, auto shutoff nozzle, proper filtration, and real tie-down points. After several weeks of fueling a pickup, a compact excavator, and a tractor, I’ve formed a solid picture of where this unit shines—and where you need to pay attention.

For clarity, I’ll refer to it simply as the AM-TANK 58.

Fit, finish, and first setup

The AM-TANK 58 is a rotomolded polyethylene tank with a lockable, UV-resistant lid that shields the pump, filter head, and fittings. The build feels stout: smooth molding, no thin spots, and cleanly installed hardware. Forklift pockets underneath and molded handles up top make sense for moving it full or empty. The tank has molded grooves that accept ratchet straps nicely, which makes securement straightforward.

It truly is low profile. In a mid-size pickup, it sits low enough that I can close a soft roll-up tonneau without bunching. Measure your bed rails and the cover’s crossbars to be sure, but the form factor is one of the big selling points.

Out of the box, the pump is pre-mounted with a particulate/water-separating filter and a 13-foot, 3/4-inch hose terminating in an automatic nozzle. The pump is rated 12 GPM, draws about 22A, and includes 20 feet of battery leads with clamps. I wired it straight to the truck battery for testing, then later added a weatherproof quick-disconnect and inline fuse to make deployment easier.

Setup notes:
- Keep the battery run as short and beefy as possible. Voltage sag at 20+ amps hurts flow.
- Crack the 2-inch fill cap (it has a three-function vent) during dispensing to ensure the tank breathes freely.
- Strap it tight; 58 gallons of diesel translates to roughly 400+ pounds of liquid weight alone.

Pump performance and what affects it

Advertised “12 GPM” is a best-case figure. In practice, my flow rate varied from about 4 to 10 GPM depending on:
- Voltage at the pump (engine running = faster).
- Filter condition (clean vs. water-logged).
- Ambient temperature (cold diesel moves slower).
- Head height and hose routing (kinks and uphill runs matter).
- Any added hose length or fittings (I added a cam-lock and occasional extension; it costs flow).

On a clean filter with the truck idling, I typically saw 10 gallons in just under a minute and a half. With a saturated filter, flow trailed off to a trickle. That’s not a pump defect; that’s the filter doing its job. If you’re drawing from questionable sources or shifting drums, plan on replacing the element more often. I now keep spare 30-micron water-blocking elements in the truck.

Priming and air were non-issues most of the time, but I did encounter one stubborn start after transporting on a bumpy gravel road. Tilting the tank slightly and cracking the vent cap helped clear air and restore prime, and it didn’t recur. If you’re struggling with weak flow, run through this checklist:
- Open the vent and confirm the lid isn’t pinching the hose.
- Ensure the clamps at the filter head and pump are tight—tiny air leaks kill flow.
- Check battery voltage under load; low voltage is a silent culprit.
- Swap in a fresh filter if the current one has seen wet or dirty fuel.

The pump’s 30-minute on/off duty cycle is plenty for a tank of this size—at 6–10 GPM, you’ll empty a significant chunk well before you hit the limit.

Filtration and fuel cleanliness

The inline particulate and water separator is a standout feature. It’s compact, doesn’t drip during changes, and provides real insurance for equipment injectors. I’d rather sacrifice flow than pass grit or water downstream. That said, filtration isn’t free: if you feed it bad fuel, expect to replace elements quickly. My workflow now is:
- Let drums or bulk deliveries settle before transferring.
- Use a drum screen or pre-filter when pulling from suspect sources.
- Keep two spare elements and O-rings on hand.

The “tell” that the element is loaded is a slower, throaty pump sound and reduced flow. Replace early; it’s cheaper than injectors.

Hose, nozzle, and day-to-day usability

The 13-foot hose reaches comfortably from the truck bed to equipment parked alongside. For refueling machines with higher fill points or awkward angles, I temporarily added a longer hose via a cam-lock. Flow took a small hit but remained acceptable. The nozzle has an auto shutoff that works reliably, and the integrated swivel is a little thing that saves a lot of hose wrestling.

The lid’s latches are metal, feel positive, and accept a padlock. I appreciate being able to secure the nozzle under the lid when parked; it keeps the weather out and honest people honest.

Noise-wise, the pump is a typical 12V whir—noticeable but not obnoxious. With the tonneau closed, sound is further muted.

Capacity and the fuel gauge reality

You’ll rarely get a true 58 gallons into any “58” portable tank. Between the expansion headspace and practical fill level, I repeatedly logged about 52–54 usable gallons. That’s normal and, in my opinion, smart. Fuel expands with temperature, and you want breathing room.

The fuel level indicator is more of a trend gauge than a lab instrument. Mine was inconsistent at first, then improved after the sender was replaced. I still trust a quick visual through the fill neck. If you’re trying to plan refills precisely, use a meter at the nozzle or track transfers by time at a known flow rate.

Portability, weight, and safety

Empty, the AM-TANK 58 is manageable for one person. With “a little fuel left,” I can slide it around the bed using the molded handles. Full, it’s a different story: think 450–500 pounds including the tank. Use the forklift pockets if you need to remove it loaded, or simply plan to pump down before moving.

Safety reminders that matter in the real world:
- This is for diesel only. Do not use it with gasoline.
- Ground bonding is good practice when transferring fuel, especially in dry conditions.
- Strap it at all four corners using the molded grooves; don’t rely on friction.
- Check your local regulations regarding transporting fuel in portable tanks. Rules vary.

The pump carries an IP55 rating, and the lid shields it well from rain and UV. I’ve had no issues leaving it in the truck through storms.

Support, spares, and longevity

I did interact with support once to address the level gauge. Response wasn’t instant, but I got what I needed without drama. Given the consumable nature of the filter, I recommend ordering a twin pack of replacement elements and stashing them in the lid compartment. Keep a few extra hose clamps, Teflon tape, and a small tube of fuel-rated thread sealant—you won’t need them often, but when you do, you’ll really need them.

After several hundred gallons moved, the system is tight with no leaks, the pump hasn’t lost steam, and the fittings have stayed put. The tank material shows no chalking or UV fade under a cover.

What I’d change

• Include a flow meter option. Knowing exactly what you dispensed is useful for tracking inventory and verifying deliveries.
• Beefier power connectors from the factory. The clamps work, but a fused quick-disconnect lead would be cleaner.
• Calibrate the level gauge better or mark the sight path with real gallon notches.

None of these are deal-breakers; they’re the sort of refinements that would elevate an already capable setup.

The bottom line

The AM-TANK 58 is a well-built, low-profile diesel transfer solution that actually fits under a tonneau and stands up to regular use. Real-world pump speed depends heavily on power and filtration, so treat the 12 GPM spec as “up to” rather than a guarantee. If you maintain the filter, keep voltage up, and strap it properly, it’s an efficient way to bring 50-plus gallons to wherever your diesel equipment lives.

Recommendation: I recommend the AM-TANK 58 for anyone who needs portable, on-vehicle diesel fueling and values integrated filtration and a compact footprint. It’s especially good for contractors, acreage owners, and anyone running diesel equipment away from the pump. Be prepared to carry spare filters, wire it correctly, and accept that the usable capacity sits in the low 50s. If you want an absolutely maintenance-free, plug-and-play setup with meter-accurate gauging, this won’t be it. For everyone else, it’s a dependable, thoughtfully designed tank that does what it promises.