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 |
|---|---|---|---|---|---|
| 1551 |
STEN NEPTUN
IMO 9322712
|
16,511 | 2007 |
12.7
|
E |
| 1552 |
STEN AURORA
IMO 9318565
|
16,596 | 2007 |
12.8
|
E |
| 1553 |
XT FORTUNE
IMO 9815628
|
13,121 | 2020 |
12.9
|
E |
| 1554 |
NEXUS
IMO 9173032
|
7,076 | 1998 |
12.9
|
E |
| 1555 |
SEASHARK
IMO 9298193
|
32,302 | 2004 |
13.1
|
E |
| 1556 |
DA HUA SHAN
IMO 9779757
|
12,972 | 2017 |
13.2
|
E |
| 1557 |
T.ADALYN
IMO 9830305
|
14,787 | 2019 |
13.3
|
E |
| 1558 |
HAI GONG YOU 309
IMO 9153214
|
12,924 | 1998 |
13.3
|
E |
| 1559 |
DIVINA
IMO 9377200
|
15,994 | 2009 |
13.4
|
E |
| 1560 |
ARDENZA
IMO 9377195
|
15,994 | 2009 |
13.4
|
E |
| 1561 |
CHEM HERO
IMO 9402823
|
16,656 | 2011 |
13.4
|
E |
| 1562 |
BIT HERO
IMO 9786645
|
9,921 | 2018 |
13.5
|
E |
| 1563 |
STEN POSEIDON
IMO 9322700
|
16,534 | 2007 |
13.6
|
E |
| 1564 |
BRO NISSUM
IMO 9340623
|
16,674 | 2008 |
13.7
|
E |
| 1565 |
T PROCYON
IMO 9569499
|
19,101 | 2021 |
13.7
|
E |
| 1566 |
LISCA NERA M
IMO 9436692
|
42,000 | 2009 |
13.7
|
E |
| 1567 |
STEN BALTIC
IMO 9307671
|
16,607 | 2005 |
13.7
|
E |
| 1568 |
ASTREA
IMO 9488839
|
11,215 | 2010 |
13.7
|
E |
| 1569 |
STEN FJELL
IMO 9460241
|
18,561 | 2010 |
13.8
|
E |
| 1570 |
BARBARICA
IMO 9383443
|
18,818 | 2008 |
13.8
|
E |
| 1571 |
LISBON
IMO 9223916
|
19,783 | 2000 |
14.0
|
E |
| 1572 |
STEN TRITON
IMO 9322695
|
16,564 | 2007 |
14.0
|
E |
| 1573 |
BRO NUUK
IMO 9323819
|
16,631 | 2008 |
14.0
|
E |
| 1574 |
WINDPOWER
IMO 1016056
|
8,768 | 2024 |
14.0
|
E |
| 1575 |
STENBERG
IMO 9283978
|
16,626 | 2003 |
14.1
|
E |
| 1576 |
THE CHIEF
IMO 9492361
|
14,912 | 2013 |
14.1
|
E |
| 1577 |
GIJON KNUTSEN
IMO 9313527
|
38,150 | 2006 |
14.2
|
E |
| 1578 |
SINAR MINAHASA
IMO 9433860
|
12,693 | 2007 |
14.2
|
E |
| 1579 |
FURE SKAGEN
IMO 9362152
|
16,958 | 2008 |
14.3
|
E |
| 1580 |
STEN ARNOLD
IMO 9371610
|
16,578 | 2008 |
14.3
|
E |
| 1581 |
DATTILO M
IMO 9333474
|
21,600 | 2006 |
14.3
|
E |
| 1582 |
STAV VIKING
IMO 9401556
|
16,628 | 2009 |
14.4
|
E |
| 1583 |
SONGA COSMOS
IMO 9457024
|
25,130 | 2010 |
14.4
|
E |
| 1584 |
PATALYA
IMO 9305180
|
16,664 | 2005 |
14.5
|
E |
| 1585 |
IEVOLI GOLD
IMO 9404376
|
17,011 | 2009 |
14.6
|
E |
| 1586 |
SRIWANGI III
IMO 9430739
|
13,954 | 2015 |
14.6
|
E |
| 1587 |
STEN MOSTER
IMO 9341184
|
16,670 | 2006 |
14.7
|
E |
| 1588 |
STEN HIDRA
IMO 9358931
|
16,670 | 2007 |
14.7
|
E |
| 1589 |
BALDO
IMO 9351749
|
11,998 | 2005 |
14.8
|
E |
| 1590 |
TIGRIS
IMO 9443841
|
12,919 | 2009 |
14.9
|
E |
| 1591 |
BAGSHOT
IMO 9938987
|
17,933 | 2023 |
14.9
|
E |
| 1592 |
CHRYSOPIGI
IMO 9303728
|
38,554 | 2006 |
14.9
|
E |
| 1593 |
FURE SPEAR
IMO 9409273
|
16,585 | 2009 |
15.0
|
E |
| 1594 |
COLORADO STAR
IMO 9527609
|
13,021 | 2010 |
15.1
|
E |
| 1595 |
STAVFJORD
IMO 9401544
|
16,635 | 2009 |
15.1
|
E |
| 1596 |
MARLIN
IMO 9453638
|
17,043 | 2011 |
15.2
|
E |
| 1597 |
CANNETO M
IMO 9359583
|
21,600 | 2008 |
15.2
|
E |
| 1598 |
GANGES STAR
IMO 9496692
|
13,013 | 2010 |
15.2
|
E |
| 1599 |
SALINA M
IMO 9340910
|
11,283 | 2007 |
15.3
|
E |
| 1600 |
EASTERN SPIRAEA
IMO 9909754
|
11,531 | 2022 |
15.5
|
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.