What we’re comparing (and why it matters)
Two numbers drive real-world tanker utility:
- Fuel you can bring / give
• Max fuel capacity = how much the tanker can carry.
• Offload at range/on-station = what receivers actually get once you’ve flown out and held. (This is the planner’s gold.) - What an hour costs
True Cost Per Flying Hour (CPFH) is rarely published consistently across countries. For U.S. fleets, a good public proxy is the DoD FY2025 “reimbursable rate” (used to bill other government users). It rolls up O&M + military personnel + an asset utilization charge. It’s not identical to internal CPFH or commercial fuel price, but it’s apples-to-apples across USAF types. Office of the Under Secretary of Defense
Caveat: Non-US operators (e.g., UK Voyager/A330 MRTT) often use service contracts or PFIs, so public “per-hour” figures include very different things. Treat cross-nation cost comparisons as directional, not exact.
Quick spec snapshots (2025)
- KC-46A Pegasus (USAF) – Fuel capacity: 212,299 lb. New-gen boom + centerline drogue, palletized cargo. U.S. Air Force+1
- KC-135R Stratotanker (USAF) – Max transfer fuel load: 200,000 lb; the long-serving global workhorse. U.S. Air Force
- KC-10A Extender (USAF, retired 2024) – Fuel capacity: 356,000+ lb; huge offload, boom + hose-and-drogue. Included below as a benchmark. U.S. Air Force+1
- A330 MRTT (Voyager KC2/KC3 et al.) – Max fuel weight: 111,000 kg (245,000 lb); brochure example: offload up to 70 t in 1 hour at 1,000 nm; 55 t available at 1,000 nm towline mission. Airbus
- KC-130J (USMC/others) – Offload: 57,500 lb via wing/external tanks; optional internal 3,600-gal tank adds ~24,392 lb potential offload. Military.com+1
- A400M (tactical tanker) – Internal fuel: up to 51 t; podded refueling for fighters/helos; can also receive fuel. Airbus
- IL-78 / IL-78M-90A – Published transferable fuel examples: 42 t at 1,000 km (Il-78) and 74 t at 1,000 km (Il-78M), per design data. Wikipedia
2025 hourly cost (public, comparable where possible)
US DoD FY2025 reimbursable rates (USD, per flight hour):
- KC-46A: $12,657–$13,463 (user class range). Office of the Under Secretary of Defense
- KC-135R/T: $20,063–$21,165. Office of the Under Secretary of Defense
- KC-10A: $18,801–$19,914 (historic; USAF retired the KC-10 in 2024). Office of the Under Secretary of Defense+1
- KC-130J (USN/USMC): $15,666–$16,802. Office of the Under Secretary of Defense
Non-US example (different basis):
- UK Voyager (A330 MRTT) PFI service cost: historical government figure ≈ £450M/year for 18,000 flying hours ⇒ ~£25,000 per hour (includes broader PFI charges/personnel, not just fuel & maintenance). Wikipedia
One-glance comparison table
| Tanker (2025) | Max fuel / transfer fuel | Example offload at range | Primary refuel gear | Public hourly cost (basis) |
|---|---|---|---|---|
| KC-46A | 212,299 lb onboard | — | Boom + centerline drogue | $12.7k–$13.5k/hr (DoD FY25 rate) U.S. Air Force+1 |
| KC-135R | 200,000 lb max transfer | 1,500 mi w/150,000 lb transfer (AF fact sheet planning datum) | Boom (w/optional drogue adapter or MPRS pods) | $20.1k–$21.2k/hr (DoD FY25) U.S. Air Force+1 |
| KC-10A (benchmark) | 356,000+ lb onboard | — | Boom + hose-and-drogue | $18.8k–$19.9k/hr (DoD FY25) U.S. Air Force+2Air & Space Forces Magazine+2 |
| A330 MRTT | 111,000 kg / 245,000 lb onboard | Up to 70 t offload in 1 hr @ 1,000 nm; 55 t available at 1,000 nm towline mission | FBW boom + 905E pods (FRU optional) | ≈£25k/hr (UK PFI service cost, not CPFH) Airbus+1 |
| KC-130J | 57,500 lb offload (wings/ext) (+~24,392 lb via 3,600-gal fuselage tank) | Tactical ranges; helo refueling capable | 2 × hose-and-drogue pods | $15.7k–$16.8k/hr (DoD FY25) Military.com+2Wikipedia+2 |
| A400M (tanker/receiver) | Up to 51 t internal fuel | Tactical/offshore tracks; helo AAR | Pods + probe (receiver capable) | — (no standardized public rate) Airbus |
| IL-78 / IL-78M | — | ~42 t @ 1,000 km (Il-78); ~74 t @ 1,000 km (Il-78M) | 3 × UPAZ pods (probe/drogue) | — (no standardized public rate) Wikipedia |
Notes:
• “Max fuel” is onboard capacity; “max transfer/available” reflects what can be offloaded (often a better planning metric).
• USAF “reimbursable rate” ≠ pure CPFH, but is a consistent public yardstick for U.S. types. Office of the Under Secretary of Defense
Who’s the 2025 “value” champ?
If you (very crudely) divide onboard fuel by FY25 U.S. reimbursable rate, you get a fuel-per-dollar snapshot:
- KC-10A ≈ 18.9 lb per $ (huge tanks at a mid-teens rate; now retired).
- KC-46A ≈ 16.8 lb per $ (modern systems, low hourly rate).
- KC-135R ≈ 10.0 lb per $ (smaller tanks, higher hourly rate vs KC-46).
- KC-130J ≈ 3.6 lb per $ (tactical mission, different use-case).
(Back-of-envelope using data above; your mission fuel offload at range is the real driver.)
Takeaway: For strategic air-to-air refueling, the KC-46A now delivers near-KC-10 capacity efficiency with a lower billed hourly rate than KC-135R—one reason it’s replacing legacy fleets. U.S. Air Force+1
Capability nuance that affects “best” choice
- Offload at range > raw capacity.
The A330 MRTT stands out on long tracks: brochure examples include offloading up to 70 t in one hour at 1,000 nm, and 55 t available at 1,000 nm towline missions—strong numbers for fighter drags and long on-station windows. Airbus - Receiver compatibility & modes.
KC-46A and A330 MRTT support boom + hose-and-drogue; KC-135R is boom-first (with options); KC-130J/A400M are drogue specialists and can refuel helicopters—a different mission class. Airbus+3U.S. Air Force+3U.S. Air Force+3 - Tactical vs strategic.
KC-130J and A400M shine in short/soft strips and low-level ops; KC-46A/A330 MRTT dominate strategic drags, high-altitude boom work, and mixed airlift + AAR roles. Military.com+1 - Legacy benchmark.
The retired KC-10A remains the pure capacity king (356k lb), but the fleet left USAF service in 2024; today’s planning pivots to KC-46A and allied A330 MRTT fleets. Wikipedia
Planner’s cheatsheet: when to pick which
- Long fighter drags / big offload at distance: A330 MRTT or KC-46A (if boom receivers dominate). Airbus+1
- Boom-only heavy receivers (B-52, E-3, etc.): KC-46A / KC-135R. U.S. Air Force+1
- Rotary-wing / expeditionary / short strip: KC-130J / A400M with pods. Military.com+1
- Benchmarking legacy capacity: KC-10A data still useful for campaign fuel math, but not a 2025 scheduling option. U.S. Air Force+1
Sources & data you can trust
- USAF fact sheets (fuel capacities, transfer loads): KC-46A, KC-135R, KC-10A. U.S. Air Force+2U.S. Air Force+2
- Airbus official (A330 MRTT specs & offload examples; A400M tanker facts). Airbus+1
- DoD FY2025 reimbursable rates (hourly): KC-46A, KC-135R/T, KC-10A, KC-130J. Office of the Under Secretary of Defense
- KC-130J references (offload & optional fuselage tank). Military.com+1
- IL-78 series (transferable fuel vs distance, published design table). Wikipedia
- UK Voyager cost context (PFI annual cost & implied per-hour). Wikipedia
- Capacity: KC-10A (ret.) > A330 MRTT ≈ KC-46A > KC-135R > A400M > KC-130J (tactical niche).
- Billed hourly (US public proxy): KC-46A is the lowest among USAF big tankers in FY2025 rate sheets, while KC-135R is higher. Office of the Under Secretary of Defense
- Mission fit beats specs: If you need helicopter AAR or dirt-strip ops, KC-130J/A400M win. For global drags and boom receivers, KC-46A/A330 MRTT dominate. For UK/Europe, remember Voyager’s published cost is a PFI service rate, not a pure CPFH—don’t compare that 1:1 with USAF reimbursable tables. Airbus+1
