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 |
|---|---|---|---|---|---|
| 453 |
AL FALAH
IMO 9828388
|
114,708 | 2021 |
3.1
|
B |
| 452 |
ATLANTIC DIAMOND
IMO 1022457
|
114,047 | 2025 |
3.1
|
B |
| 451 |
T.SADBERK
IMO 9804136
|
157,453 | 2017 |
3.1
|
B |
| 454 |
PENELOPE
IMO 9941726
|
114,763 | 2023 |
3.1
|
B |
| 456 |
DRAGAO DO MAR
IMO 9453822
|
157,055 | 2014 |
3.2
|
B |
| 455 |
BARCELONA SPIRIT
IMO 9578634
|
158,482 | 2011 |
3.2
|
B |
| 461 |
SEAWAYS RIO GRANDE
IMO 9593438
|
159,056 | 2010 |
3.2
|
B |
| 460 |
ECO MALIBU
IMO 9902823
|
157,668 | 2021 |
3.2
|
B |
| 459 |
EROTOKRITOS
IMO 9978377
|
114,939 | 2024 |
3.2
|
B |
| 458 |
SOLOMOS
IMO 9933200
|
115,286 | 2022 |
3.2
|
B |
| 457 |
DESIMI
IMO 9395305
|
296,865 | 2011 |
3.2
|
B |
| 464 |
DUNE
IMO 1021788
|
113,667 | 2025 |
3.2
|
B |
| 463 |
DELTA ATLANTICA
IMO 9419101
|
161,762 | 2011 |
3.2
|
B |
| 465 |
SEACROSS
IMO 9297890
|
163,292 | 2003 |
3.2
|
B |
| 462 |
MINERVA ZENOBIA
IMO 9787182
|
114,671 | 2018 |
3.2
|
B |
| 466 |
VADELA
IMO 9996408
|
159,220 | 2024 |
3.2
|
B |
| 469 |
EMERALDWAY
IMO 9907653
|
158,362 | 2020 |
3.2
|
B |
| 468 |
STAR ENERGY
IMO 9773935
|
158,409 | 2016 |
3.2
|
B |
| 467 |
BRANDS HATCH
IMO 1034199
|
113,006 | 2025 |
3.2
|
B |
| 470 |
SEARHYTHM
IMO 9880350
|
111,963 | 2021 |
3.2
|
B |
| 473 |
TORM HERDIS
IMO 9797981
|
115,109 | 2018 |
3.2
|
B |
| 472 |
MALIBU
IMO 9776731
|
158,692 | 2017 |
3.2
|
B |
| 471 |
ON PHOENIX
IMO 9893228
|
114,623 | 2021 |
3.2
|
B |
| 474 |
RAN DF
IMO 9953470
|
114,575 | 2023 |
3.2
|
B |
| 477 |
ALASKA
IMO 9302607
|
163,250 | 2006 |
3.2
|
B |
| 476 |
SEALEGEND
IMO 9906568
|
115,648 | 2020 |
3.2
|
B |
| 475 |
YANNIS P.
IMO 9411343
|
158,149 | 2010 |
3.2
|
B |
| 479 |
ATLANTIC M
IMO 9907237
|
156,668 | 2022 |
3.2
|
B |
| 481 |
NEW DISCOVERY
IMO 9269075
|
159,199 | 2003 |
3.2
|
B |
| 478 |
NORTH STAR
IMO 9978676
|
114,898 | 2025 |
3.2
|
B |
| 488 |
RS TARA
IMO 9765354
|
160,036 | 2016 |
3.2
|
B |
| 482 |
ELANDRA TERN
IMO 9945318
|
109,999 | 2024 |
3.2
|
B |
| 480 |
FRANKOPAN
IMO 9796731
|
114,305 | 2017 |
3.2
|
B |
| 487 |
AIGEORGIS
IMO 9891660
|
116,092 | 2021 |
3.2
|
B |
| 486 |
ANTIGUA I
IMO 9753363
|
157,392 | 2016 |
3.2
|
B |
| 485 |
TARIF
IMO 9828390
|
114,799 | 2021 |
3.2
|
B |
| 484 |
HAFNIA THALASSA
IMO 9800324
|
109,990 | 2019 |
3.2
|
B |
| 483 |
ZUMA
IMO 9998559
|
115,167 | 2025 |
3.2
|
B |
| 489 |
SEAWAYS SABINE
IMO 9594755
|
158,493 | 2012 |
3.2
|
B |
| 491 |
CAPTAIN SPIRO
IMO 9692856
|
113,796 | 2014 |
3.2
|
B |
| 490 |
SEA ONYX
IMO 9922108
|
156,646 | 2022 |
3.2
|
B |
| 492 |
ATLANTA SPIRIT
IMO 9578646
|
158,650 | 2011 |
3.2
|
B |
| 496 |
SEGWAY
IMO 1050959
|
156,030 | 2025 |
3.2
|
B |
| 497 |
CAP THEODORA
IMO 9380740
|
158,819 | 2008 |
3.2
|
B |
| 495 |
AIOLOS
IMO 9987031
|
115,643 | 2025 |
3.2
|
B |
| 494 |
ARISTEA
IMO 9791315
|
112,794 | 2018 |
3.2
|
B |
| 493 |
ANTARCTICA
IMO 9910492
|
163,128 | 2022 |
3.2
|
B |
| 498 |
SEARUNNER
IMO 9765029
|
114,129 | 2017 |
3.2
|
B |
| 500 |
PROTEUS IWONA
IMO 9914670
|
109,999 | 2022 |
3.3
|
B |
| 499 |
TORTUGA
IMO 9998547
|
115,302 | 2025 |
3.3
|
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.