Open study, cut two · CC BY 4.0 · EU MRV reporting year 2025
Engine type and the 2026 methane bill
The obvious question after the first cut is which machinery carries the cost. The honest answer first: the EU MRV export has no engine-type field, so no filing can be attributed to Otto-cycle dual fuel, high-pressure gas injection or lean-burn spark ignition from this dataset. What the filings do support is a slip-intensity cut — the median methane each LNG-signature ship in a segment actually reported.
65 ships
in high-slip segments
median above 3,000 t CO2e each
34.1%
of the fleet's methane
457,412 t CO2e of 1,342,231 t
EUR 36,592,960
a year at EUR 80/t
from those segments alone
Slip bands, and what they suggest
Bands are set on the median filed CH4 (CO2e) per LNG-signature ship in each segment: high above 3,000 t, mid above 1,500 t, low below. Thresholds are published so the cut can be reproduced — or contested — with different cut points.
High slip signature
34.1%
of fleet methane · 65 LNG-signature ships across 4 segments
Consistent with low-pressure Otto-cycle dual-fuel machinery (four-stroke DFDE or two-stroke X-DF), the families the literature associates with the largest crankcase and scavenge slip, especially at part load.
Mid slip signature
58.1%
of fleet methane · 269 LNG-signature ships across 4 segments
Mixed segment. Both Otto-cycle and diesel-cycle gas injection plausibly present; the median alone does not separate them.
Low slip signature
7.5%
of fleet methane · 25 LNG-signature ships across 5 segments
Consistent with high-pressure diesel-cycle gas injection (ME-GI / ME-GA) or lean-burn spark ignition, where filed methane is an order of magnitude below the Otto-cycle segments — but equally consistent with a handful of conventional ships just over the LNG-signature line.
Every segment that filed methane
| Segment | LNG-signature ships | CH4 (t CO2e) | Median per ship (t) | CH4 vs CO2 | Band |
|---|---|---|---|---|---|
| LNG carrier | 250 | 732,931 | 2,047 | 14.46% | Mid slip signature |
| Container ship | 22 | 189,244 | 3,915 | 0.67% | High slip signature |
| Ro-pax ship | 29 | 133,858 | 3,253 | 1.48% | High slip signature |
| Passenger ship (Cruise Passenger ship) | 10 | 122,292 | 11,566 | 2.31% | High slip signature |
| Oil tanker | 4 | 36,147 | 721 | 0.37% | Low slip signature |
| Vehicle carrier | 6 | 30,957 | 815 | 1.33% | Low slip signature |
| Gas carrier | 12 | 26,855 | 1,840 | 1.64% | Mid slip signature |
| Chemical tanker | 5 | 15,873 | 1,272 | 0.29% | Low slip signature |
| Ro-ro ship | 3 | 13,260 | 1,723 | 0.37% | Mid slip signature |
| Passenger ship | 4 | 12,018 | 3,266 | 5.41% | High slip signature |
| General cargo ship | 7 | 11,160 | 929 | 0.21% | Low slip signature |
| Other ship types (Offshore) | 3 | 7,139 | 945 | 0.36% | Low slip signature |
| Other ship types | 4 | 6,544 | 1,557 | 0.53% | Mid slip signature |
| Bulk carrier | 0 | 3,433 | — | 0.05% | No LNG signature |
| Container/ro-ro cargo ship | 0 | 317 | — | 0.04% | No LNG signature |
| Refrigerated cargo carrier | 0 | 197 | — | 0.04% | No LNG signature |
| Combination carrier | 0 | 6 | — | 0.04% | No LNG signature |
What this cut cannot do
- EU MRV publishes no engine-type field. Nothing here identifies an engine on any individual ship, and no ship is named.
- Slip bands are set on the median filed CH4 per LNG-signature ship within a ship type. A type with a mixed fleet will average across families and can land in a band that describes neither well.
- The band-to-combustion-family reading is an inference from published slip behaviour, not an observation. Confirming it requires joining the IMO numbers to an engine register (Equasis, IHS or Clarksons); that join has not been run here.
- Bands move if the thresholds move. They are published above so the cut can be reproduced or contested with different cut points.
- Everything is priced from filed mass. The concentration figures do not depend on the GWP basis or the carbon price.
The definitive answer needs the IMO numbers joined to an engine register. That join is the next cut; until it is run and published, treat the bands as a shape, not a verdict.
Run it yourself
The underlying per-segment data is the same open dataset as the first cut, free to reuse, repost or contest under CC BY 4.0.
Source: EU MRV verified emission reports (THETIS-MRV), reporting years 2024 and 2025, European Maritime Safety Agency. · Cite: Full Ahead Maritime (2026), The 2026 EU ETS Methane Bill, CC BY 4.0 - https://fullaheadmaritime.com/methane-slip-ets-cost