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 2024. 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 |
|---|---|---|---|---|---|
| 555 |
SEARHYTHM
IMO 9880350
|
111,963 | 2021 |
3.3
|
B |
| 554 |
STI ORCHARD
IMO 9690834
|
109,999 | 2014 |
3.3
|
B |
| 556 |
PIS KERINCI
IMO 9838242
|
109,994 | 2019 |
3.3
|
B |
| 553 |
EAGLE BRASILIA
IMO 9795062
|
114,000 | 2019 |
3.3
|
B |
| 552 |
AMBELOS
IMO 9801524
|
114,674 | 2017 |
3.3
|
B |
| 551 |
TORM GRACE
IMO 9531648
|
119,456 | 2012 |
3.3
|
B |
| 559 |
DELTA MARIA
IMO 9700691
|
157,031 | 2015 |
3.3
|
B |
| 561 |
ELANDRA SWALLOW
IMO 9945291
|
109,999 | 2023 |
3.3
|
B |
| 558 |
GLADIATOR
IMO 9378864
|
149,944 | 2008 |
3.3
|
B |
| 557 |
AIFANOURIOS
IMO 9891696
|
116,015 | 2021 |
3.3
|
B |
| 560 |
AQUASURAZO
IMO 9785720
|
110,000 | 2017 |
3.3
|
B |
| 562 |
FRANKOPAN
IMO 9796731
|
114,305 | 2017 |
3.3
|
B |
| 563 |
FRONT LEOPARD
IMO 9703320
|
109,900 | 2016 |
3.3
|
B |
| 566 |
HAFNIA DESPINA
IMO 9796494
|
109,990 | 2019 |
3.3
|
B |
| 565 |
PROMETHEUS LIGHT
IMO 9801976
|
114,601 | 2019 |
3.3
|
B |
| 564 |
AL KHTAM
IMO 9823534
|
114,644 | 2021 |
3.3
|
B |
| 572 |
BERGEN TS
IMO 9737400
|
113,039 | 2017 |
3.3
|
B |
| 571 |
RAVA
IMO 9796743
|
114,385 | 2017 |
3.3
|
B |
| 570 |
AEGEAN HORIZON
IMO 9326811
|
158,738 | 2007 |
3.3
|
B |
| 569 |
CLEAROCEAN AJAX
IMO 9850692
|
113,252 | 2019 |
3.3
|
B |
| 568 |
PASCHALIS DD
IMO 9765378
|
159,812 | 2018 |
3.3
|
B |
| 567 |
LENI P.
IMO 9594133
|
158,640 | 2010 |
3.3
|
B |
| 575 |
CHIOS DF
IMO 9953482
|
114,580 | 2024 |
3.3
|
B |
| 577 |
MINERVA ALEXANDRA
IMO 9892999
|
115,484 | 2021 |
3.3
|
B |
| 574 |
ALASKA
IMO 9302607
|
163,250 | 2006 |
3.3
|
B |
| 573 |
FRONT FUTURE
IMO 9887815
|
109,896 | 2021 |
3.3
|
B |
| 576 |
ARACHTHOS I
IMO 9935143
|
115,198 | 2023 |
3.3
|
B |
| 578 |
SIGRUN
IMO 9612052
|
156,092 | 2013 |
3.4
|
B |
| 581 |
PSERIMOS
IMO 9578658
|
158,670 | 2011 |
3.4
|
B |
| 580 |
MEGAN GLORY
IMO 9953054
|
115,569 | 2023 |
3.4
|
B |
| 579 |
GREEN ADVENTURE
IMO 9927201
|
114,319 | 2022 |
3.4
|
B |
| 582 |
SFL OTTAWA
IMO 9593012
|
159,500 | 2015 |
3.4
|
B |
| 587 |
TORM HANNAH
IMO 9712864
|
109,999 | 2016 |
3.4
|
B |
| 586 |
NAVIG8 PRIDE LHJ
IMO 9947366
|
109,999 | 2023 |
3.4
|
B |
| 585 |
RIVERA
IMO 9777943
|
113,000 | 2015 |
3.4
|
B |
| 584 |
SEAROVER
IMO 9765017
|
114,049 | 2017 |
3.4
|
B |
| 583 |
STAVANGER TS
IMO 9737395
|
113,004 | 2017 |
3.4
|
B |
| 589 |
ALMI ODYSSEY
IMO 9579559
|
157,787 | 2013 |
3.4
|
B |
| 592 |
TORM KRISTINA
IMO 9694646
|
114,322 | 2015 |
3.4
|
B |
| 594 |
CLEAR STARS
IMO 9868778
|
113,848 | 2020 |
3.4
|
B |
| 591 |
NEWBURY
IMO 9920497
|
112,095 | 2022 |
3.4
|
B |
| 595 |
PHAETHON
IMO 9412098
|
158,267 | 2009 |
3.4
|
B |
| 590 |
SEFERIS
IMO 9937024
|
113,839 | 2023 |
3.4
|
B |
| 588 |
AMADES
IMO 9903126
|
112,708 | 2022 |
3.4
|
B |
| 593 |
ELENI
IMO 9432062
|
149,999 | 2011 |
3.4
|
B |
| 599 |
RED SUN
IMO 9384564
|
115,325 | 2008 |
3.4
|
B |
| 598 |
ALMI GLOBE
IMO 9579511
|
157,787 | 2012 |
3.4
|
B |
| 597 |
EAGLE BRISBANE
IMO 9795050
|
113,400 | 2015 |
3.4
|
B |
| 596 |
FRONT COUGAR
IMO 9686649
|
109,896 | 2016 |
3.4
|
B |
| 600 |
CIELO DI CAGLIARI
IMO 9781281
|
74,999 | 2018 |
3.4
|
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 2024 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.