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 |
|---|---|---|---|---|---|
| 1601 |
STEN NORDIC
IMO 9351567
|
16,657 | 2005 |
15.7
|
E |
| 1602 |
STEN PONTOS
IMO 9323584
|
16,427 | 2007 |
15.7
|
E |
| 1603 |
ATRIA
IMO 9492842
|
13,005 | 2010 |
15.7
|
E |
| 1604 |
CHALLAH
IMO 9933913
|
9,137 | 2022 |
15.7
|
E |
| 1605 |
SAMBA
IMO 9310305
|
19,117 | 2005 |
16.0
|
E |
| 1606 |
VULCANELLO M.
IMO 9337779
|
11,288 | 2006 |
16.1
|
E |
| 1607 |
ASPHALT SPIRIT
IMO 9612557
|
14,484 | 2012 |
16.2
|
E |
| 1608 |
DING HENG 23
IMO 9841421
|
9,013 | 2024 |
16.4
|
E |
| 1609 |
ASTRAL
IMO 9371878
|
11,317 | 2006 |
16.5
|
E |
| 1610 |
RUBIKON 78
IMO 9312078
|
16,642 | 2005 |
16.5
|
E |
| 1611 |
PANAREA M
IMO 9329148
|
11,420 | 2006 |
16.5
|
E |
| 1612 |
RUBIKON 202
IMO 9344423
|
16,979 | 2007 |
16.6
|
E |
| 1613 |
PRIME
IMO 9267558
|
14,750 | 2004 |
16.7
|
E |
| 1614 |
ARROW STAR 1
IMO 9435313
|
13,030 | 2007 |
16.7
|
E |
| 1615 |
LACHIN
IMO 9821469
|
7,757 | 2020 |
16.7
|
E |
| 1616 |
ASTINA
IMO 9320063
|
11,283 | 2006 |
16.8
|
E |
| 1617 |
SONGA OPAL
IMO 9473913
|
17,588 | 2009 |
16.9
|
E |
| 1618 |
CALAJUNCO M
IMO 9359571
|
21,600 | 2007 |
16.9
|
E |
| 1619 |
BRO ANNA
IMO 9344435
|
16,867 | 2008 |
17.3
|
E |
| 1620 |
MERENGUE
IMO 9309980
|
38,431 | 2007 |
17.4
|
E |
| 1621 |
HAVVA ANA
IMO 9997385
|
8,817 | 2024 |
17.4
|
E |
| 1622 |
LUMINA T
IMO 9312080
|
16,772 | 2006 |
17.6
|
E |
| 1623 |
YELLOW TRADER
IMO 9292840
|
158,609 | 2004 |
17.8
|
E |
| 1624 |
STELLA POLARIS
IMO 9187057
|
8,297 | 1999 |
17.9
|
E |
| 1625 |
LETTIE PG
IMO 1018846
|
10,810 | 2025 |
17.9
|
E |
| 1626 |
OASIS II
IMO 9167150
|
34,985 | 2000 |
18.4
|
E |
| 1627 |
MOUNT OLYMPUS
IMO 9260081
|
40,011 | 2003 |
18.5
|
E |
| 1628 |
XT PEACE
IMO 9980265
|
7,493 | 2023 |
18.6
|
E |
| 1629 |
BLACK SHARK
IMO 9480655
|
8,476 | 2010 |
18.7
|
E |
| 1630 |
SONGA SAPPHIRE
IMO 9444467
|
17,596 | 2008 |
18.8
|
E |
| 1631 |
MELIGUNIS M
IMO 9451214
|
11,258 | 2008 |
18.8
|
E |
| 1632 |
HEINRICH ESSBERGER
IMO 9939814
|
7,109 | 2024 |
18.9
|
E |
| 1633 |
LISELOTTE ESSBERGER
IMO 9939785
|
7,134 | 2023 |
19.0
|
E |
| 1634 |
3B DESTINY
IMO 9799446
|
7,645 | 2017 |
19.0
|
E |
| 1635 |
DHAN LAXMI
IMO 9284788
|
50,353 | 2004 |
19.1
|
E |
| 1636 |
SONGA PEARL
IMO 9444455
|
17,539 | 2008 |
19.1
|
E |
| 1637 |
VEMAHONESTY
IMO 9448891
|
6,388 | 2009 |
19.2
|
E |
| 1638 |
JOHN T. ESSBERGER
IMO 9939797
|
7,100 | 2023 |
19.3
|
E |
| 1639 |
BAYRAKLI
IMO 9418391
|
3,799 | 2009 |
19.4
|
E |
| 1640 |
BAUSTELLA
IMO 9812133
|
7,995 | 2018 |
19.5
|
E |
| 1641 |
ROSE PG
IMO 9799032
|
7,420 | 2017 |
19.7
|
E |
| 1642 |
IVER BITUMEN
IMO 9438949
|
6,482 | 2009 |
20.1
|
E |
| 1643 |
IVER AMBASSADOR
IMO 9768514
|
7,673 | 2015 |
20.1
|
E |
| 1644 |
IVER BEAUTY
IMO 9588263
|
6,175 | 2011 |
20.4
|
E |
| 1645 |
POESTELLA
IMO 9803235
|
8,021 | 2017 |
20.7
|
E |
| 1646 |
EVIE PG
IMO 9396359
|
9,990 | 2007 |
20.9
|
E |
| 1647 |
SIRI KNUTSEN
IMO 9247168
|
37,494 | 2004 |
20.9
|
E |
| 1648 |
ZHUANG YUAN AO
IMO 9650339
|
12,000 | 2012 |
21.4
|
E |
| 1649 |
SHENG HUA WAN
IMO 9814416
|
7,640 | 2018 |
21.5
|
E |
| 1650 |
LILSTELLA
IMO 9794771
|
7,944 | 2016 |
21.5
|
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.