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 |
|---|---|---|---|---|---|
| 951 |
NISSOS PAROS
IMO 9592290
|
115,722 | 2010 |
4.3
|
C |
| 952 |
MINERVA SOPHIA
IMO 9382762
|
115,748 | 2009 |
4.3
|
C |
| 953 |
CALIDA
IMO 9522128
|
115,812 | 2008 |
4.3
|
C |
| 954 |
SEALEO
IMO 9473066
|
107,505 | 2012 |
4.3
|
C |
| 955 |
PACIFIC A. DORODCHI
IMO 9732266
|
109,999 | 2016 |
4.4
|
C |
| 956 |
STI JERMYN
IMO 9722596
|
109,999 | 2016 |
4.4
|
C |
| 957 |
SEA JAGUAR
IMO 9482627
|
114,024 | 2011 |
4.4
|
C |
| 958 |
SILVER MILLIE
IMO 9692363
|
49,642 | 2015 |
4.4
|
C |
| 959 |
MINERVA NOUNOU
IMO 9309423
|
114,850 | 2006 |
4.4
|
C |
| 960 |
BAHRA
IMO 9595008
|
110,761 | 2012 |
4.4
|
C |
| 961 |
BLUE INTEGRITY
IMO 9388778
|
108,926 | 2005 |
4.4
|
C |
| 962 |
CLEAROCEAN MUSTANG
IMO 9893761
|
49,999 | 2020 |
4.4
|
C |
| 963 |
HELLAS CALAFIA
IMO 9798088
|
49,810 | 2018 |
4.4
|
C |
| 964 |
NORTH SEA
IMO 9760495
|
106,340 | 2016 |
4.4
|
C |
| 965 |
YASA GOLDEN BOSPHORUS
IMO 9334038
|
115,867 | 2007 |
4.4
|
C |
| 966 |
TORM THOR
IMO 9712292
|
49,666 | 2015 |
4.4
|
C |
| 967 |
DUBAI CHARM
IMO 9402495
|
115,514 | 2010 |
4.4
|
C |
| 968 |
STI ALEXIS
IMO 9696694
|
109,999 | 2015 |
4.4
|
C |
| 969 |
GULF CORAL
IMO 9389851
|
74,999 | 2009 |
4.4
|
C |
| 970 |
MARI JONE
IMO 9725316
|
49,999 | 2016 |
4.4
|
C |
| 971 |
ATHENS VOYAGER
IMO 9337391
|
105,614 | 2007 |
4.4
|
C |
| 972 |
SEASTAR
IMO 9373656
|
116,049 | 2008 |
4.4
|
C |
| 973 |
SEA JEWEL
IMO 9607722
|
112,081 | 2013 |
4.4
|
C |
| 974 |
GEM NO. 3
IMO 9774343
|
79,920 | 2014 |
4.4
|
C |
| 975 |
CHIOS I
IMO 9792187
|
156,984 | 2017 |
4.4
|
C |
| 976 |
SEA STAR
IMO 9607710
|
112,147 | 2010 |
4.4
|
C |
| 977 |
ALYARMOUK
IMO 9356438
|
116,038 | 2008 |
4.4
|
C |
| 978 |
LILLESAND
IMO 9336397
|
105,786 | 2007 |
4.5
|
C |
| 979 |
PINTAIL PACIFIC
IMO 9983891
|
49,773 | 2024 |
4.5
|
C |
| 980 |
SYNNØVE KNUTSEN
IMO 9868388
|
152,868 | 2020 |
4.5
|
C |
| 981 |
EAGLE PETROLINA
IMO 9858553
|
153,226 | 2020 |
4.5
|
C |
| 982 |
NAVIG8 MACALLISTER
IMO 9482873
|
75,618 | 2012 |
4.5
|
C |
| 983 |
MINERVA PISCES
IMO 9410179
|
105,475 | 2008 |
4.5
|
C |
| 984 |
SEAPRINCESS
IMO 9373668
|
115,948 | 2005 |
4.5
|
C |
| 985 |
SUNNY LIGER
IMO 9332626
|
74,997 | 2008 |
4.5
|
C |
| 986 |
ALEXANDER
IMO 9826720
|
113,170 | 2017 |
4.5
|
C |
| 987 |
MINERVA ELPIDA
IMO 9440526
|
112,793 | 2010 |
4.5
|
C |
| 988 |
KMARIN RESTRAINT
IMO 9683075
|
109,526 | 2017 |
4.5
|
C |
| 989 |
DUGI OTOK
IMO 9334727
|
108,414 | 2008 |
4.5
|
C |
| 990 |
EAGLE PARAISO
IMO 9858577
|
153,264 | 2020 |
4.5
|
C |
| 991 |
ATROTOS
IMO 9953432
|
50,113 | 2023 |
4.5
|
D |
| 992 |
HAFNIA EGRET
IMO 9607174
|
49,999 | 2014 |
4.5
|
D |
| 993 |
NAVIG8 MARTINEZ
IMO 9482847
|
75,599 | 2011 |
4.5
|
D |
| 994 |
SEA HYMN
IMO 9412036
|
116,337 | 2011 |
4.5
|
D |
| 995 |
ALBERTA
IMO 9486922
|
104,760 | 2010 |
4.5
|
D |
| 996 |
ALDER EXPRESS
IMO 9934163
|
49,832 | 2020 |
4.5
|
D |
| 997 |
BOUVARDIA
IMO 9935595
|
111,009 | 2022 |
4.5
|
D |
| 998 |
VALLESINA
IMO 9417311
|
109,089 | 2009 |
4.5
|
D |
| 999 |
PRIMERO
IMO 9741815
|
106,329 | 2016 |
4.5
|
D |
| 1000 |
SEMERU
IMO 9388376
|
105,777 | 2008 |
4.5
|
D |
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.