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 |
|---|---|---|---|---|---|
| 901 |
JAARLI
IMO 9892432
|
112,459 | 2021 |
4.2
|
C |
| 902 |
NISSOS SERIFOS
IMO 9592264
|
115,688 | 2012 |
4.2
|
C |
| 903 |
KMARIN RENOWN
IMO 9683013
|
109,693 | 2016 |
4.2
|
C |
| 904 |
MAERSK CYPRUS
IMO 9786217
|
49,919 | 2020 |
4.2
|
C |
| 905 |
PALLADIUM
IMO 9773923
|
113,221 | 2017 |
4.2
|
C |
| 906 |
EUROINTEGRITY
IMO 9410648
|
105,291 | 2009 |
4.2
|
C |
| 907 |
DUBAI ATTRACTION
IMO 9422536
|
115,459 | 2011 |
4.2
|
C |
| 908 |
ADVANTAGE START
IMO 9466570
|
156,644 | 2011 |
4.2
|
C |
| 909 |
STI ELYSEES
IMO 9688829
|
109,999 | 2014 |
4.2
|
C |
| 910 |
AEGEAN NOBILITY
IMO 9345441
|
115,814 | 2007 |
4.2
|
C |
| 911 |
MAERSK CANCUN
IMO 9786138
|
49,919 | 2018 |
4.2
|
C |
| 912 |
AQUALEGACY
IMO 9601833
|
115,763 | 2012 |
4.2
|
C |
| 913 |
INDIGO SUN
IMO 9592288
|
115,724 | 2012 |
4.2
|
C |
| 914 |
GLADIATOR
IMO 9378864
|
149,944 | 2008 |
4.2
|
C |
| 915 |
STI GAUNTLET
IMO 9717137
|
109,999 | 2017 |
4.2
|
C |
| 916 |
TOVE KNUTSEN
IMO 9868376
|
152,868 | 2020 |
4.2
|
C |
| 917 |
KMARIN RESPECT
IMO 9683001
|
109,584 | 2016 |
4.3
|
C |
| 918 |
FPMC P IDEAL
IMO 9459709
|
109,994 | 2012 |
4.3
|
C |
| 919 |
CABO MISAKI
IMO 9755062
|
74,177 | 2017 |
4.3
|
C |
| 920 |
ANIKITOS
IMO 9953444
|
50,113 | 2023 |
4.3
|
C |
| 921 |
PHOENIX ADMIRAL
IMO 9482603
|
114,024 | 2007 |
4.3
|
C |
| 922 |
JAG SPARROW
IMO 9297412
|
74,999 | 2005 |
4.3
|
C |
| 923 |
KMARIN RESOURCE
IMO 9683037
|
109,483 | 2016 |
4.3
|
C |
| 924 |
ADVANTAGE SPRING
IMO 9466582
|
156,596 | 2010 |
4.3
|
C |
| 925 |
BAYOU SUN
IMO 9911537
|
49,999 | 2022 |
4.3
|
C |
| 926 |
OLIB
IMO 9334739
|
108,433 | 2009 |
4.3
|
C |
| 927 |
MARCILIO DIAS
IMO 9453858
|
157,055 | 2015 |
4.3
|
C |
| 928 |
PACIFIC NAFSIKA
IMO 9732278
|
109,999 | 2015 |
4.3
|
C |
| 929 |
TORM EVELYN
IMO 9456927
|
74,213 | 2011 |
4.3
|
C |
| 930 |
HOVDEN SPIRIT
IMO 9596997
|
105,276 | 2010 |
4.3
|
C |
| 931 |
NORDIC LIGHT
IMO 9436446
|
158,475 | 2010 |
4.3
|
C |
| 932 |
STI SYMPHONY
IMO 9719692
|
109,999 | 2016 |
4.3
|
C |
| 933 |
TP AFFINITY
IMO 9645401
|
114,070 | 2016 |
4.3
|
C |
| 934 |
HAFNIA ANDREA
IMO 9688415
|
50,040 | 2015 |
4.3
|
C |
| 935 |
LUZON SPIRIT
IMO 9572276
|
109,581 | 2011 |
4.3
|
C |
| 936 |
CAPE BILBAO
IMO 1035052
|
50,607 | 2025 |
4.3
|
C |
| 937 |
YASA GOLDEN DARDANELLES
IMO 9339985
|
110,828 | 2008 |
4.3
|
C |
| 938 |
SEA VALIANT
IMO 9420629
|
107,488 | 2010 |
4.3
|
C |
| 939 |
BLUE PRINCE
IMO 9429182
|
109,010 | 2009 |
4.3
|
C |
| 940 |
STELLATA
IMO 9732230
|
109,991 | 2016 |
4.3
|
C |
| 941 |
DELTA STAR
IMO 9458016
|
115,618 | 2013 |
4.3
|
C |
| 942 |
FOSSIL
IMO 9379624
|
115,760 | 2009 |
4.3
|
C |
| 943 |
NORTHERNLIGHT
IMO 9577123
|
74,565 | 2012 |
4.3
|
C |
| 944 |
LADY HENRIETTA
IMO 9604380
|
111,815 | 2012 |
4.3
|
C |
| 945 |
CLIO
IMO 9396660
|
112,705 | 2008 |
4.3
|
C |
| 946 |
CABO FROWARD
IMO 9311359
|
74,543 | 2006 |
4.3
|
C |
| 947 |
CALYPSO
IMO 9899296
|
111,930 | 2021 |
4.3
|
C |
| 948 |
SAGA
IMO 9528031
|
115,738 | 2011 |
4.3
|
C |
| 949 |
KMARIN RESOLUTION
IMO 9683051
|
109,484 | 2016 |
4.3
|
C |
| 950 |
MINERVA SOPHIA
IMO 9382762
|
115,748 | 2009 |
4.3
|
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.