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 2024. 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 |
|---|---|---|---|---|---|
| 1701 |
T PROCYON
IMO 9569499
|
19,101 | 2021 |
12.8
|
E |
| 1702 |
HAI GONG YOU 309
IMO 9153214
|
12,924 | 1998 |
12.8
|
E |
| 1703 |
STARLIGHT II
IMO 9377652
|
37,847 | 2007 |
12.8
|
E |
| 1704 |
STEN AURORA
IMO 9318565
|
16,596 | 2007 |
12.9
|
E |
| 1705 |
EASTERN NYMPHAEA
IMO 9827994
|
13,498 | 2019 |
12.9
|
E |
| 1706 |
ASTREA
IMO 9488839
|
11,215 | 2010 |
12.9
|
E |
| 1707 |
STEN HIDRA
IMO 9358931
|
16,670 | 2007 |
12.9
|
E |
| 1708 |
STEN BERGEN
IMO 9407988
|
16,655 | 2009 |
13.0
|
E |
| 1709 |
THE CHIEF
IMO 9492361
|
14,912 | 2013 |
13.1
|
E |
| 1710 |
ARDENZA
IMO 9377195
|
15,994 | 2009 |
13.1
|
E |
| 1711 |
GIJON KNUTSEN
IMO 9313527
|
38,150 | 2006 |
13.1
|
E |
| 1712 |
SPECTRUM
IMO 9535412
|
21,999 | 2009 |
13.2
|
E |
| 1713 |
STEN BALTIC
IMO 9307671
|
16,607 | 2005 |
13.3
|
E |
| 1714 |
ANNA MARIA P
IMO 9288368
|
47,278 | 2005 |
13.3
|
E |
| 1715 |
STEN SUOMI
IMO 9378723
|
16,619 | 2008 |
13.5
|
E |
| 1716 |
JIN ZHOU WAN
IMO 9802580
|
13,265 | 2017 |
13.6
|
E |
| 1717 |
BRO NUUK
IMO 9323819
|
16,631 | 2008 |
13.7
|
E |
| 1718 |
NEW AMORGOS
IMO 9370836
|
107,510 | 2008 |
13.7
|
E |
| 1719 |
HAI GONG YOU 306
IMO 9150614
|
16,376 | 1999 |
13.8
|
E |
| 1720 |
IEVOLI GOLD
IMO 9404376
|
17,011 | 2009 |
13.9
|
E |
| 1721 |
STEN NORDIC
IMO 9351567
|
16,657 | 2005 |
13.9
|
E |
| 1722 |
STEN TRITON
IMO 9322695
|
16,564 | 2007 |
14.0
|
E |
| 1723 |
DIVINA
IMO 9377200
|
15,994 | 2009 |
14.0
|
E |
| 1724 |
STEN PONTOS
IMO 9323584
|
16,427 | 2007 |
14.0
|
E |
| 1725 |
BARBARICA
IMO 9383443
|
18,818 | 2008 |
14.1
|
E |
| 1726 |
STAVFJORD
IMO 9401544
|
16,635 | 2009 |
14.1
|
E |
| 1727 |
STENBERG
IMO 9283978
|
16,626 | 2003 |
14.1
|
E |
| 1728 |
STEN FJELL
IMO 9460241
|
18,561 | 2010 |
14.1
|
E |
| 1729 |
ASPHALT TERANGA
IMO 9263942
|
9,230 | 2005 |
14.2
|
E |
| 1730 |
T.ADALYN
IMO 9830305
|
14,787 | 2019 |
14.2
|
E |
| 1731 |
LEOPOLD
IMO 9173032
|
7,076 | 1998 |
14.3
|
E |
| 1732 |
NEW LEGEND
IMO 9230505
|
159,435 | 2002 |
14.3
|
E |
| 1733 |
FURE SKAGEN
IMO 9362152
|
16,958 | 2008 |
14.6
|
E |
| 1734 |
STEN MOSTER
IMO 9341184
|
16,670 | 2006 |
14.6
|
E |
| 1735 |
STEN ARNOLD
IMO 9371610
|
16,578 | 2008 |
14.6
|
E |
| 1736 |
ARROW STAR 1
IMO 9435313
|
13,030 | 2007 |
14.6
|
E |
| 1737 |
TIGRIS
IMO 9443841
|
12,919 | 2009 |
14.7
|
E |
| 1738 |
STEN NEPTUN
IMO 9322712
|
16,511 | 2007 |
14.8
|
E |
| 1739 |
STAV VIKING
IMO 9401556
|
16,628 | 2009 |
14.9
|
E |
| 1740 |
CANNETO M
IMO 9359583
|
21,600 | 2008 |
14.9
|
E |
| 1741 |
PATRONA I
IMO 9305178
|
16,716 | 2004 |
15.1
|
E |
| 1742 |
SRIWANGI III
IMO 9430739
|
13,954 | 2015 |
15.3
|
E |
| 1743 |
DATTILO M
IMO 9333474
|
21,600 | 2006 |
15.3
|
E |
| 1744 |
PATALYA
IMO 9305180
|
16,664 | 2005 |
15.4
|
E |
| 1745 |
VULCANELLO M.
IMO 9337779
|
11,288 | 2006 |
15.7
|
E |
| 1746 |
NORSIGN BREEZE
IMO 9365477
|
16,748 | 2006 |
15.8
|
E |
| 1747 |
RUBIKON 78
IMO 9312078
|
16,642 | 2005 |
15.8
|
E |
| 1748 |
STEN POSEIDON
IMO 9322700
|
16,534 | 2007 |
15.9
|
E |
| 1749 |
PATARA
IMO 9344423
|
16,979 | 2007 |
16.1
|
E |
| 1750 |
ROSSI A. DESGAGNES
IMO 9804435
|
14,919 | 2019 |
16.1
|
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 2024 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.