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 |
|---|---|---|---|---|---|
| 703 |
STI GRATITUDE
IMO 9722182
|
109,999 | 2017 |
3.6
|
C |
| 702 |
STI BROADWAY
IMO 9690846
|
109,999 | 2014 |
3.6
|
C |
| 704 |
BERGEN TS
IMO 9737400
|
113,039 | 2017 |
3.6
|
C |
| 701 |
SEAROVER
IMO 9765017
|
114,049 | 2017 |
3.6
|
C |
| 705 |
ELENI
IMO 9432062
|
149,999 | 2011 |
3.7
|
C |
| 708 |
NAVIG8 PASSION
IMO 9853278
|
109,992 | 2015 |
3.7
|
C |
| 707 |
GREEN ANAX
IMO 9927213
|
114,405 | 2023 |
3.7
|
C |
| 706 |
CIELO ROSSO
IMO 9778301
|
74,999 | 2018 |
3.7
|
C |
| 709 |
SOHO SQUARE
IMO 9505819
|
114,900 | 2012 |
3.7
|
C |
| 713 |
SEAWAYS SHENANDOAH
IMO 9607966
|
112,691 | 2014 |
3.7
|
C |
| 712 |
ADVANTAGE ANGEL
IMO 9779953
|
113,563 | 2017 |
3.7
|
C |
| 711 |
FRONT FAVOUR
IMO 9903968
|
109,893 | 2021 |
3.7
|
C |
| 710 |
BLUEFIN PEARL
IMO 9397808
|
111,402 | 2009 |
3.7
|
C |
| 714 |
NAVE COSMOS
IMO 9971707
|
115,650 | 2022 |
3.7
|
C |
| 716 |
ALFA FINLANDIA
IMO 9823041
|
109,089 | 2019 |
3.7
|
C |
| 715 |
POLAR ACE
IMO 9721504
|
109,999 | 2018 |
3.7
|
C |
| 717 |
STI VENETO
IMO 9690822
|
109,999 | 2015 |
3.7
|
C |
| 719 |
ELANDRA SWALLOW
IMO 9945291
|
109,999 | 2023 |
3.7
|
C |
| 718 |
ANGELONIA
IMO 9901051
|
111,039 | 2021 |
3.7
|
C |
| 721 |
ELANDRA GULF
IMO 9749544
|
113,364 | 2016 |
3.7
|
C |
| 720 |
AGISTRI
IMO 9597018
|
158,464 | 2012 |
3.7
|
C |
| 723 |
SPETSES LADY
IMO 9831074
|
109,992 | 2020 |
3.7
|
C |
| 722 |
KRITI ENERGY
IMO 9935636
|
156,740 | 2022 |
3.7
|
C |
| 724 |
PROTEUS REBECCA
IMO 9914682
|
109,999 | 2022 |
3.7
|
C |
| 725 |
LILA MARSEILLE
IMO 9418614
|
156,557 | 2011 |
3.7
|
C |
| 726 |
STI LAUREN
IMO 9696711
|
109,999 | 2015 |
3.7
|
C |
| 730 |
STI LOTUS
IMO 9838230
|
109,995 | 2017 |
3.7
|
C |
| 729 |
BALLA
IMO 9749556
|
113,293 | 2017 |
3.7
|
C |
| 728 |
LAMU
IMO 1021776
|
113,633 | 2025 |
3.7
|
C |
| 727 |
GREEN AURA
IMO 9808168
|
112,684 | 2019 |
3.7
|
C |
| 731 |
JOSE DO PATROCINIO
IMO 9453860
|
157,055 | 2007 |
3.7
|
C |
| 732 |
BOTAFOGO
IMO 9395329
|
106,892 | 2010 |
3.7
|
C |
| 733 |
MARLIN HERA
IMO 9729221
|
74,197 | 2017 |
3.7
|
C |
| 734 |
PACIFIC GARNET
IMO 9893084
|
113,306 | 2021 |
3.7
|
C |
| 737 |
SFL TIGRIS
IMO 9982691
|
109,899 | 2025 |
3.7
|
C |
| 736 |
HAFNIA TAGUS
IMO 9766205
|
74,151 | 2017 |
3.7
|
C |
| 735 |
SEALOYALTY
IMO 9783928
|
108,610 | 2018 |
3.7
|
C |
| 738 |
MARAN POSEIDON
IMO 9402926
|
158,267 | 2010 |
3.7
|
C |
| 741 |
DOLPHIN PEARL
IMO 9402237
|
114,824 | 2006 |
3.7
|
C |
| 740 |
MINERVA KARTERIA
IMO 9787170
|
114,780 | 2018 |
3.7
|
C |
| 739 |
ORCA PEARL
IMO 9402249
|
114,821 | 2009 |
3.7
|
C |
| 748 |
PATROCLUS
IMO 9413834
|
158,267 | 2009 |
3.8
|
C |
| 747 |
PACIFIC PEARL
IMO 9893072
|
113,306 | 2021 |
3.8
|
C |
| 746 |
HAFNIA LANGUEDOC
IMO 9941685
|
109,999 | 2023 |
3.8
|
C |
| 745 |
SEAVOYAGER
IMO 9408762
|
109,085 | 2009 |
3.8
|
C |
| 744 |
KMARIN RIGOUR
IMO 9683049
|
109,475 | 2016 |
3.8
|
C |
| 743 |
VELOS EMERALD
IMO 9402213
|
115,042 | 2008 |
3.8
|
C |
| 742 |
KMARIN REASON
IMO 9683087
|
109,483 | 2017 |
3.8
|
C |
| 750 |
SAMOS
IMO 9486934
|
104,649 | 2010 |
3.8
|
C |
| 749 |
BORDEIRA
IMO 9529499
|
158,513 | 2013 |
3.8
|
C |
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.