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 |
|---|---|---|---|---|---|
| 751 |
SEARUBY
IMO 9759795
|
114,073 | 2017 |
3.7
|
C |
| 753 |
SEARANGER
IMO 9759800
|
114,055 | 2017 |
3.7
|
C |
| 752 |
TORM GLORIA
IMO 9461843
|
119,456 | 2011 |
3.7
|
C |
| 754 |
SKS DRIVA
IMO 9428970
|
119,456 | 2010 |
3.7
|
C |
| 756 |
SEA SAPPHIRE
IMO 9935600
|
156,669 | 2022 |
3.7
|
C |
| 755 |
ESTRELLA
IMO 9696761
|
106,282 | 2014 |
3.7
|
C |
| 757 |
RAN DF
IMO 9953470
|
114,575 | 2023 |
3.7
|
C |
| 758 |
STI SELATAR
IMO 9729245
|
109,999 | 2017 |
3.7
|
C |
| 763 |
NAVIG8 PROVIDENCE
IMO 9947378
|
109,995 | 2023 |
3.7
|
C |
| 762 |
OCEANUS
IMO 9337004
|
150,265 | 2008 |
3.7
|
C |
| 761 |
HAFNIA EXECUTIVE
IMO 9735622
|
74,431 | 2016 |
3.7
|
C |
| 760 |
PACIFIC PEARL
IMO 9893072
|
113,306 | 2021 |
3.7
|
C |
| 759 |
POLAR ACE
IMO 9721504
|
109,999 | 2018 |
3.7
|
C |
| 765 |
DUBAI BRILLIANCE
IMO 9422550
|
115,617 | 2011 |
3.8
|
C |
| 764 |
ALDEBARAN
IMO 9853400
|
112,802 | 2019 |
3.8
|
C |
| 768 |
MARCILIO DIAS
IMO 9453858
|
157,055 | 2015 |
3.8
|
C |
| 766 |
PACIFIC RUBY
IMO 9893034
|
113,306 | 2021 |
3.8
|
C |
| 769 |
KWK EXCELSUS
IMO 9728411
|
114,716 | 2016 |
3.8
|
C |
| 772 |
ELANDRA GULF
IMO 9749544
|
113,364 | 2016 |
3.8
|
C |
| 771 |
NEW DISCOVERY
IMO 9269075
|
159,199 | 2003 |
3.8
|
C |
| 770 |
ANGELONIA
IMO 9901051
|
111,039 | 2021 |
3.8
|
C |
| 767 |
MARATHON TS
IMO 9737371
|
113,651 | 2017 |
3.8
|
C |
| 773 |
HANOVER SQUARE
IMO 9783992
|
114,366 | 2019 |
3.8
|
C |
| 774 |
KMARIN REASON
IMO 9683087
|
109,483 | 2017 |
3.8
|
C |
| 778 |
SEACHARM
IMO 9773765
|
112,179 | 2018 |
3.8
|
C |
| 777 |
STI LAUREN
IMO 9696711
|
109,999 | 2015 |
3.8
|
C |
| 776 |
STI SOLACE
IMO 9708588
|
109,999 | 2013 |
3.8
|
C |
| 775 |
MARAN POSEIDON
IMO 9402926
|
158,267 | 2010 |
3.8
|
C |
| 779 |
KAPSALI
IMO 9587312
|
158,546 | 2011 |
3.8
|
C |
| 781 |
MEDITERRANEAN VOYAGER
IMO 9857858
|
115,165 | 2018 |
3.8
|
C |
| 780 |
DUBAI BEAUTY
IMO 9422548
|
115,382 | 2011 |
3.8
|
C |
| 784 |
STI CONNAUGHT
IMO 9697600
|
109,999 | 2013 |
3.8
|
C |
| 783 |
MILTON SANTOS
IMO 9453884
|
157,055 | 2017 |
3.8
|
C |
| 782 |
STI STABILITY
IMO 9712840
|
109,999 | 2016 |
3.8
|
C |
| 785 |
NISSOS DELOS
IMO 9592305
|
115,690 | 2012 |
3.8
|
C |
| 787 |
ALMI HORIZON
IMO 9579494
|
157,787 | 2011 |
3.8
|
C |
| 790 |
SEATRIBUTE
IMO 9857468
|
111,932 | 2020 |
3.8
|
C |
| 789 |
AMAZON FORTITUDE
IMO 9820544
|
72,836 | 2018 |
3.8
|
C |
| 788 |
STEMNITSA
IMO 9693070
|
109,999 | 2013 |
3.8
|
C |
| 786 |
STELLATA
IMO 9732230
|
109,991 | 2016 |
3.8
|
C |
| 791 |
HAFNIA TAGUS
IMO 9766205
|
74,151 | 2017 |
3.8
|
C |
| 792 |
SUEZ PROTOPIA
IMO 9380893
|
160,391 | 2008 |
3.8
|
C |
| 796 |
FRONT JAGUAR
IMO 9703332
|
109,900 | 2016 |
3.8
|
C |
| 795 |
PROMETHEUS ENERGY
IMO 9801988
|
114,459 | 2019 |
3.8
|
C |
| 794 |
STARLING
IMO 9737527
|
74,033 | 2016 |
3.8
|
C |
| 793 |
AGRARI
IMO 9389083
|
107,009 | 2009 |
3.8
|
C |
| 800 |
SEA PUMA
IMO 9802176
|
114,560 | 2019 |
3.8
|
C |
| 799 |
PENELOPE
IMO 9941726
|
114,763 | 2023 |
3.8
|
C |
| 798 |
MACHADO DE ASSIS
IMO 9453872
|
157,055 | 2016 |
3.8
|
C |
| 797 |
STI SUPREME
IMO 9719721
|
109,999 | 2016 |
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 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.