Most Emission-Efficient Oil Tankers
Ships ranked by AER (Annual Efficiency Ratio) — grams of CO₂ emitted per tonne of deadweight carried one nautical mile (g CO₂/dwt·nm), the IMO carbon-intensity metric behind the CII rating — from official EU MRV emissions data for reporting year 2025. Lower is greener. Pick a segment and size class to see the greenest vessels first.
| # | Vessel | Size (DWT) | Built | Carbon intensity — AER (g CO₂/dwt·nm) | Grade |
|---|---|---|---|---|---|
| 349 |
JILL GLORY
IMO 9959917
|
115,415 | 2021 |
3.0
|
B |
| 353 |
KAREKARE
IMO 9787986
|
159,638 | 2017 |
3.0
|
B |
| 351 |
P. BEL AIR
IMO 9794056
|
157,285 | 2019 |
3.0
|
B |
| 354 |
TENACITY VENTURE
IMO 9773052
|
114,439 | 2017 |
3.0
|
B |
| 358 |
NJORD DF
IMO 9953468
|
114,545 | 2023 |
3.0
|
B |
| 364 |
PLATA LUCKY
IMO 9358292
|
307,284 | 2009 |
3.0
|
B |
| 357 |
SAMSARA
IMO 9792228
|
159,855 | 2017 |
3.0
|
B |
| 363 |
SEAWAYS BRAZOS
IMO 9594731
|
158,537 | 2012 |
3.0
|
B |
| 362 |
EAGLE SAN JUAN
IMO 9594846
|
157,850 | 2012 |
3.0
|
B |
| 361 |
MATALA
IMO 9776743
|
158,714 | 2017 |
3.0
|
B |
| 356 |
YOKOSUKA SPIRIT
IMO 9932402
|
112,174 | 2023 |
3.0
|
B |
| 359 |
SEAGRACE
IMO 9934826
|
157,746 | 2022 |
3.0
|
B |
| 355 |
NORDIC BREEZE
IMO 9588445
|
158,597 | 2011 |
3.0
|
B |
| 360 |
MARATHON TS
IMO 9737371
|
113,651 | 2017 |
3.0
|
B |
| 367 |
PHAEDRA
IMO 9989091
|
114,808 | 2025 |
3.0
|
B |
| 369 |
NEW SPIROS
IMO 1023322
|
115,000 | 2025 |
3.0
|
B |
| 366 |
MONTE SERANTES
IMO 9841615
|
156,584 | 2019 |
3.0
|
B |
| 370 |
STAVANGER STAR
IMO 9984871
|
115,382 | 2024 |
3.0
|
B |
| 365 |
NISSOS SIKINOS
IMO 9884033
|
157,447 | 2020 |
3.0
|
B |
| 368 |
SEAVISION
IMO 9790971
|
158,480 | 2018 |
3.0
|
B |
| 371 |
MARLIN LOME
IMO 9823572
|
114,841 | 2022 |
3.0
|
B |
| 373 |
MH GLADIATOR
IMO 1023932
|
114,595 | 2025 |
3.0
|
B |
| 372 |
STALLION
IMO 9399478
|
157,048 | 2006 |
3.0
|
B |
| 376 |
ISABELLA
IMO 1014096
|
113,959 | 2025 |
3.0
|
B |
| 375 |
NAVE NEUTRINO
IMO 9971733
|
115,806 | 2024 |
3.0
|
B |
| 374 |
CHIOS DF
IMO 9953482
|
114,580 | 2024 |
3.0
|
B |
| 377 |
STOIC WARRIOR
IMO 1028762
|
156,885 | 2025 |
3.0
|
B |
| 382 |
CAPTAIN MICHAEL
IMO 9531480
|
157,648 | 2012 |
3.0
|
B |
| 381 |
RODOS
IMO 1024948
|
115,069 | 2023 |
3.0
|
B |
| 380 |
MARAN HERMIONE
IMO 9779379
|
157,755 | 2017 |
3.0
|
B |
| 379 |
KARPATHOS
IMO 1024962
|
115,058 | 2026 |
3.0
|
B |
| 378 |
TP INTREPID
IMO 1034187
|
113,720 | 2025 |
3.0
|
B |
| 384 |
NORDIC ZENITH
IMO 9588469
|
158,645 | 2011 |
3.0
|
B |
| 383 |
DELTA TOLMI
IMO 9429027
|
157,487 | 2010 |
3.0
|
B |
| 388 |
FONTANA
IMO 9792541
|
159,430 | 2017 |
3.0
|
B |
| 387 |
SONANGOL HUILA
IMO 9575565
|
157,871 | 2012 |
3.0
|
B |
| 386 |
DALI
IMO 9787936
|
115,281 | 2018 |
3.0
|
B |
| 385 |
NAVE PHOTON
IMO 9971721
|
115,752 | 2024 |
3.0
|
B |
| 390 |
TORM KRISTINA
IMO 9694646
|
114,322 | 2015 |
3.0
|
B |
| 392 |
SEAGUARDIAN
IMO 9891919
|
112,157 | 2021 |
3.0
|
B |
| 389 |
SUNRISEWAY
IMO 9907665
|
158,307 | 2022 |
3.0
|
B |
| 393 |
SEAWAYS FRIO
IMO 9596985
|
159,000 | 2012 |
3.0
|
B |
| 391 |
MARAN PENELOPE
IMO 9402914
|
158,266 | 2009 |
3.0
|
B |
| 396 |
SEAHORSE 1
IMO 9956006
|
113,385 | 2024 |
3.1
|
B |
| 398 |
SFL ALBANY
IMO 9874246
|
158,060 | 2020 |
3.1
|
B |
| 397 |
NAVE PERSEUS
IMO 9993896
|
115,812 | 2025 |
3.1
|
B |
| 395 |
TAHOE SPIRIT
IMO 9427641
|
156,870 | 2010 |
3.1
|
B |
| 394 |
CELESTE NOVA
IMO 9534054
|
318,510 | 2013 |
3.1
|
B |
| 400 |
NORDIC STAR
IMO 9748679
|
157,737 | 2016 |
3.1
|
B |
| 399 |
NAUTILUS I
IMO 9298765
|
163,927 | 2006 |
3.1
|
B |
Which engines power the greenest fleets?
The main engine is the single largest CO₂ source on board — typically well over 80% of a ship's emissions come from propulsion. We aggregated this ranking the other way around: every engine design is scored by the measured carbon intensity of the vessels carrying it, licensee-built units merged under their design brand. The verdict from the 2025 data — modern dual-fuel designs like MAN B&W's ME-GI and WinGD's X-DF families, together with EGR/SCR-abated and ultra-long-stroke G-type engines, consistently power the most emission-friendly ships in service.
AER (Annual Efficiency Ratio) = annual CO₂ emissions ÷ (deadweight × distance sailed), the IMO carbon-intensity metric used for CII ratings. It is built only from measured CO₂, distance and deadweight — not the self-reported cargo transport-work figure, which is unreliable. Implausible outliers (top 2% per segment) are excluded. Grade A–E reflects each vessel's rank within its segment. Source: EMSA THETIS-MRV.