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 |
|---|---|---|---|---|---|
| 1501 |
FURE VEN
IMO 9983102
|
17,945 | 2025 |
9.5
|
E |
| 1502 |
WATSON
IMO 9858759
|
34,746 | 2019 |
9.6
|
E |
| 1503 |
ARDBEG
IMO 1055428
|
18,467 | 2025 |
9.6
|
E |
| 1504 |
PIONEER
IMO 9260079
|
40,055 | 2003 |
9.6
|
E |
| 1505 |
OTTOMANA
IMO 9299214
|
27,836 | 2006 |
9.6
|
E |
| 1506 |
GOLDEN BANYAN
IMO 1055844
|
18,444 | 2025 |
9.7
|
E |
| 1507 |
FURE VISKAR
IMO 9980320
|
17,953 | 2024 |
9.7
|
E |
| 1508 |
FURE VYL
IMO 9983956
|
17,952 | 2024 |
9.8
|
E |
| 1509 |
WHITE ALLEGRA
IMO 9973353
|
17,779 | 2023 |
9.8
|
E |
| 1510 |
ASENA
IMO 9274628
|
37,188 | 2004 |
9.8
|
E |
| 1511 |
ANWAAR AL NASER
IMO 9313450
|
29,006 | 2005 |
9.8
|
E |
| 1512 |
DAN CISNE
IMO 9513440
|
59,335 | 2011 |
9.9
|
E |
| 1513 |
SOUTHERN OWL
IMO 9773143
|
26,057 | 2016 |
10.0
|
E |
| 1514 |
XT PROSPERITY
IMO 9989560
|
13,185 | 2024 |
10.0
|
E |
| 1515 |
ANWAAR AL KHALIJ
IMO 9313424
|
29,006 | 2005 |
10.1
|
E |
| 1516 |
STI MERAUX
IMO 9681118
|
50,300 | 2012 |
10.1
|
E |
| 1517 |
SEASPRAT
IMO 9380477
|
40,598 | 2007 |
10.1
|
E |
| 1518 |
CASTILLO DE ARTEAGA
IMO 9871012
|
37,430 | 2019 |
10.2
|
E |
| 1519 |
NEW LEGEND
IMO 9230505
|
159,435 | 2002 |
10.3
|
E |
| 1520 |
ASTANA
IMO 9904053
|
13,823 | 2022 |
10.3
|
E |
| 1521 |
DAN SABIA
IMO 9513438
|
59,317 | 2012 |
10.3
|
E |
| 1522 |
STI HAMMERSMITH
IMO 9706463
|
38,734 | 2015 |
10.4
|
E |
| 1523 |
OSTRO I
IMO 1021697
|
18,653 | 2025 |
10.4
|
E |
| 1524 |
STARLIGHT II
IMO 9377652
|
37,847 | 2007 |
10.5
|
E |
| 1525 |
SEATROUT
IMO 9352303
|
40,600 | 2006 |
10.6
|
E |
| 1526 |
STEN SUOMI
IMO 9378723
|
16,619 | 2008 |
10.6
|
E |
| 1527 |
YANBU
IMO 9376816
|
38,374 | 2008 |
10.6
|
E |
| 1528 |
STI COMANDANTE
IMO 9686857
|
38,734 | 2014 |
10.6
|
E |
| 1529 |
PUTUOSHAN
IMO 9286542
|
19,822 | 2004 |
10.6
|
E |
| 1530 |
BLUE SKY
IMO 9413016
|
105,491 | 2009 |
10.6
|
E |
| 1531 |
NATIG ALIYEV
IMO 9194000
|
19,800 | 2002 |
10.7
|
E |
| 1532 |
SEAPIKE
IMO 9423449
|
43,550 | 2009 |
10.9
|
E |
| 1533 |
ATLANTIC ASPHALT
IMO 9798428
|
17,763 | 2017 |
11.0
|
E |
| 1534 |
SEACONGER
IMO 9352298
|
32,200 | 2005 |
11.1
|
E |
| 1535 |
WONDER MIMOSA
IMO 9312901
|
37,620 | 2006 |
11.1
|
E |
| 1536 |
DURGA
IMO 9260005
|
37,198 | 2003 |
11.4
|
E |
| 1537 |
GOLDEN CEDAR
IMO 1055856
|
18,417 | 2025 |
11.4
|
E |
| 1538 |
HAI GONG YOU 306
IMO 9150614
|
16,376 | 1999 |
11.5
|
E |
| 1539 |
SARACENA
IMO 9334325
|
20,500 | 2007 |
11.5
|
E |
| 1540 |
RINELLA M
IMO 9351529
|
40,441 | 2006 |
11.7
|
E |
| 1541 |
STEN BERGEN
IMO 9407988
|
16,655 | 2009 |
11.9
|
E |
| 1542 |
KUBA
IMO 9383089
|
8,525 | 2007 |
12.0
|
E |
| 1543 |
T RIGEL
IMO 9585039
|
20,919 | 2021 |
12.1
|
E |
| 1544 |
DA MING SHAN
IMO 9779745
|
12,980 | 2016 |
12.2
|
E |
| 1545 |
AGNES PG
IMO 1018858
|
10,795 | 2025 |
12.2
|
E |
| 1546 |
STEN BOTHNIA
IMO 9378735
|
16,611 | 2008 |
12.3
|
E |
| 1547 |
LIDER KEREM
IMO 9394076
|
13,330 | 2024 |
12.4
|
E |
| 1548 |
STEN FRIGG
IMO 9407976
|
16,587 | 2009 |
12.6
|
E |
| 1549 |
ANWAAR AFRIQYA
IMO 9275268
|
34,656 | 2004 |
12.6
|
E |
| 1550 |
HANUMAN
IMO 9295048
|
34,620 | 2004 |
12.7
|
E |
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.