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 |
|---|---|---|---|---|---|
| 1351 |
STI DUCHESSA
IMO 9669938
|
49,990 | 2012 |
5.8
|
D |
| 1352 |
INGRID KNUTSEN
IMO 9649225
|
111,634 | 2013 |
5.8
|
D |
| 1353 |
TORM THOR
IMO 9712292
|
49,666 | 2015 |
5.8
|
D |
| 1354 |
ENERGY ARIADNE
IMO 9906087
|
49,812 | 2021 |
5.8
|
D |
| 1355 |
EAGLE BLANE
IMO 9833101
|
128,427 | 2020 |
5.8
|
D |
| 1356 |
STAR MERLIN
IMO 9325609
|
53,755 | 2007 |
5.8
|
D |
| 1357 |
TORM PHILIPPINES
IMO 9440136
|
46,838 | 2010 |
5.8
|
D |
| 1358 |
ALEGRIA I
IMO 9543536
|
104,494 | 2012 |
5.9
|
D |
| 1359 |
TORM THAMES
IMO 9318333
|
47,036 | 2005 |
5.9
|
D |
| 1360 |
APNOIA
IMO 9448152
|
74,811 | 2009 |
5.9
|
D |
| 1361 |
CHAMPION ENDURANCE
IMO 9288813
|
46,803 | 2005 |
5.9
|
D |
| 1362 |
ARVIN
IMO 9374272
|
47,134 | 2008 |
5.9
|
D |
| 1363 |
GAMSUNORO
IMO 9677313
|
105,638 | 2014 |
5.9
|
D |
| 1364 |
STI QUEENS
IMO 9707273
|
49,990 | 2015 |
5.9
|
D |
| 1365 |
ESTIA
IMO 9327035
|
73,711 | 2007 |
5.9
|
D |
| 1366 |
HELLAS FIGHTER
IMO 9722625
|
49,997 | 2015 |
5.9
|
D |
| 1367 |
IMPERIAL
IMO 9400849
|
46,646 | 2009 |
5.9
|
D |
| 1368 |
ADVANTAGE PIONEER
IMO 9577070
|
74,552 | 2011 |
5.9
|
D |
| 1369 |
MAERSK MARU
IMO 9581447
|
48,020 | 2006 |
5.9
|
D |
| 1370 |
UOG IOANNIS V
IMO 9485629
|
73,338 | 2008 |
5.9
|
D |
| 1371 |
GRACE LEO
IMO 9380051
|
47,409 | 2009 |
5.9
|
D |
| 1372 |
STRIMON
IMO 9798973
|
49,999 | 2015 |
5.9
|
D |
| 1373 |
NORDIC JOSEPHINE
IMO 9284374
|
74,045 | 2007 |
6.0
|
D |
| 1374 |
LONDON STAR
IMO 9330343
|
73,869 | 2006 |
6.0
|
D |
| 1375 |
KAROLOS
IMO 9410208
|
162,418 | 2009 |
6.0
|
D |
| 1376 |
CLEAROCEAN HICKORY
IMO 9916616
|
49,999 | 2021 |
6.0
|
D |
| 1377 |
CL MARGARET MITCHELL
IMO 9943372
|
49,353 | 2024 |
6.0
|
D |
| 1378 |
MARLIN AQUAMARINE
IMO 9721906
|
49,999 | 2016 |
6.0
|
D |
| 1379 |
SUCCESS
IMO 9418133
|
50,571 | 2009 |
6.0
|
D |
| 1380 |
TORM INDIA
IMO 9440033
|
46,838 | 2010 |
6.0
|
D |
| 1381 |
STI MEMPHIS
IMO 9681156
|
49,995 | 2014 |
6.0
|
D |
| 1382 |
SOFIA II
IMO 9364239
|
105,400 | 2008 |
6.0
|
D |
| 1383 |
TORM SINGAPORE
IMO 9434230
|
49,999 | 2011 |
6.0
|
D |
| 1384 |
HARRIS
IMO 9379038
|
40,960 | 2009 |
6.0
|
D |
| 1385 |
NANSEN SPIRIT
IMO 9438860
|
109,239 | 2010 |
6.0
|
D |
| 1386 |
DUBAI ANGEL
IMO 9422524
|
115,502 | 2010 |
6.0
|
D |
| 1387 |
TORM LILLY
IMO 9392470
|
53,116 | 2009 |
6.0
|
D |
| 1388 |
JAG PRAKASH
IMO 9315721
|
47,848 | 2007 |
6.0
|
D |
| 1389 |
GREEN PLANET
IMO 9669914
|
50,844 | 2014 |
6.0
|
D |
| 1390 |
LARGO SEA
IMO 9746279
|
49,990 | 2016 |
6.1
|
D |
| 1391 |
NAVE PULSAR
IMO 9379313
|
49,990 | 2007 |
6.1
|
D |
| 1392 |
TORM LOUISE
IMO 9392482
|
53,049 | 2009 |
6.1
|
D |
| 1393 |
HAFNIA SWIFT
IMO 9713844
|
49,999 | 2016 |
6.1
|
D |
| 1394 |
AMUNDSEN SPIRIT
IMO 9438858
|
109,289 | 2010 |
6.1
|
D |
| 1395 |
HIGH SEAS
IMO 9455703
|
51,678 | 2007 |
6.1
|
D |
| 1396 |
MAERSK MISSISSIPPI
IMO 9555319
|
47,990 | 2010 |
6.1
|
D |
| 1397 |
VALLE BIANCA
IMO 9387580
|
50,633 | 2007 |
6.1
|
D |
| 1398 |
JOYCE
IMO 9338814
|
47,344 | 2007 |
6.1
|
D |
| 1399 |
TORM MALAYSIA
IMO 9443164
|
49,999 | 2011 |
6.1
|
D |
| 1400 |
SILVER EBURNA
IMO 9718416
|
49,737 | 2016 |
6.1
|
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 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.