Diesel transfer tanks compared: sizes, weights, and specs
Pick a transfer tank by three things: what your truck can carry full, whether it needs to be approved for gasoline, and the shape that fits your bed. Diesel weighs about 6.9 pounds a gallon (EPRI), so a full 100-gallon steel tank weighs over 800 pounds. Stay at 119 gallons or less for diesel to avoid bulk hazmat rules (J.J. Keller).
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Below are popular pickup tanks side by side, with specs from the makers' listings. We haven't tested these tanks; this is a spec comparison, not a ranking. For the legal rules and setup, see diesel transfer tank laws and setup.
Side-by-side specs
| Tank | Material | Gallons | L × W × H | Empty | Full of diesel* | Approved fuels |
|---|---|---|---|---|---|---|
| RDS 50-gal rectangular | Aluminum, 0.125 in. | 50 | 55 × 14 × 16 in. | 55 lb | 400 lb | Diesel, gasoline, or aviation fuel (DOT approved) |
| RDS 80-gal rectangular | Aluminum, 0.125 in. | 80 | 50 × 20 × 19 in. | 76 lb | 628 lb | Diesel, gasoline, or aviation fuel (DOT approved) |
| RDS 95-gal L combo with toolbox | Aluminum, 0.125 in. | 92 (max fill) | 57 × 30 × 19 in. | 140 lb | 775 lb | Diesel, gasoline, or aviation fuel (DOT approved) |
| Transfer Flow 80-gal refueling tank | 14-gauge aluminized steel | 80 | 47 × 23 × 25.75 in. | 146 lb | 698 lb | Diesel |
| Better Built 100-gal rectangular (29211677) | 14-gauge steel | 100 | 45¼ × 24 × 24 in. (catalog) | 142 lb | 832 lb | Combustible fuels such as diesel; not for gasoline; private use |
Specs from each product listing (linked), and the Better Built catalog (Better Built). *Full weight = empty weight plus capacity × 6.9 lb per gallon of diesel (EPRI); it doesn't include a pump, hose, or toolbox contents. Listings change; confirm specs before you buy.
Read the capacity carefully. The RDS "95-gallon" L combo lists a maximum fill capacity of 92 gallons (RDS listing). Better Built's catalog and Tractor Supply's listing give different widths for the same 100-gallon tank (24 vs. 31 inches) (Better Built catalog), so measure your bed against the maker's drawing.
Shop: RDS tanks on Amazon; Better Built tanks on Amazon; Transfer Flow tanks on Amazon.
Payload: the number that decides your size
Find the payload on your door-jamb sticker, then subtract everything else you carry. From the table above:
- A 50-gallon aluminum tank is about 400 pounds full, which most half-ton pickups can carry with room to spare.
- An 80-gallon tank runs about 628 pounds full in aluminum and 698 in steel, a 70-pound difference.
- A 100-gallon steel tank is about 832 pounds full, before the pump, hose, and tools.
Add the pump, hose reel, toolbox contents, and passengers. If the total is close to your payload, go smaller or go aluminum.
Diesel-only vs. gasoline-approved
This is the spec that matters most if you'll ever haul gasoline.
- RDS lists its aluminum tanks as "DOT approved" for diesel, gasoline, or aviation fuel (RDS 80-gallon listing).
- Better Built says its tanks are for combustible fuels such as diesel, are "SOLELY FOR PRIVATE USE and not for interstate commerce or commercial applications," and that their design does not meet Title 49, the federal transportation rules (Better Built catalog).
- Transfer Flow's 80-gallon tank above is listed for diesel (Transfer Flow listing). Transfer Flow makes separate gasoline tanks under a DOT special permit (see the rules guide).
If you use the tank for work, check that its approvals fit commercial use, not just private use.
Shapes
| Shape | Good for | Example |
|---|---|---|
| Rectangular | Most capacity for the footprint; sits behind the cab | RDS 80, Transfer Flow 80, Better Built 100 |
| L-shaped | Leaves room for a crossover toolbox or flat bed space beside the tank | Better Built makes 75-, 88-, and 100-gallon L tanks (Better Built catalog) |
| Combo with toolbox | Fuel and tool storage in one unit | RDS 95-gallon L combo |
Features to check
- Baffles to cut sloshing; all the tanks above list them
- A rollover vent. RDS lists a rollover safety valve. Better Built says its tanks must be vented at all times (Better Built catalog)
- Fittings: 2-inch fill and pump openings are standard on these tanks; a bottom drain makes water removal easy
- A level gauge, standard on some RDS models
- Mounting hardware included; never strap a tank in loose
Pick a pump to match: see how to choose a 12V fuel transfer pump.
FAQ
What's the best size transfer tank?
The biggest one your truck's payload can carry full, up to 119 gallons for diesel. Over 119 gallons is bulk packaging and needs placards (J.J. Keller). See the full-weight table above.
Can I put gasoline in any transfer tank?
No. Only in a tank approved for it. RDS lists its aluminum tanks as DOT-approved for diesel, gasoline, or aviation fuel (RDS 80-gallon listing). Better Built says its tanks are for combustible fuels like diesel and don't meet DOT regulations for transportation (Better Built catalog).
Steel or aluminum?
Aluminum is lighter and doesn't rust; steel usually costs less. On a half-ton pickup, the weight difference can decide what size you can carry.
Sources
- RDS 50-gallon rectangular transfer tank (Tractor Supply listing)
- RDS 80-gallon rectangular transfer tank (Tractor Supply listing)
- RDS 95-gallon L transfer tank combo (Tractor Supply listing)
- Transfer Flow 80-gallon diesel refueling tank (Tractor Supply listing)
- Better Built 100-gallon rectangular steel tank (Tractor Supply listing)
- Better Built transfer tank catalog
- J.J. Keller: Hauling diesel in transfer tanks
- EPRI / Southwest Research Institute: Winterizing Diesel Fuel (diesel density)
Specs are the makers' and retailers' listings as of October 28, 2026; we haven't independently tested these tanks. Confirm approvals and dimensions before buying.