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 |
|---|---|---|---|---|---|
| 301 |
MONTE URBASA
IMO 9785835
|
156,400 | 2018 |
2.8
|
A |
| 302 |
SILVERWAY
IMO 9742912
|
157,781 | 2017 |
2.8
|
A |
| 303 |
RUNNER
IMO 9749518
|
158,594 | 2014 |
2.8
|
A |
| 304 |
ITHAKI WARRIOR
IMO 9765366
|
159,962 | 2017 |
2.8
|
A |
| 307 |
ORIENT M
IMO 9907225
|
156,729 | 2022 |
2.8
|
A |
| 306 |
SEA GARNET
IMO 9772943
|
158,454 | 2015 |
2.8
|
A |
| 305 |
APACHE
IMO 9749489
|
158,594 | 2016 |
2.8
|
A |
| 309 |
RIO SPIRIT
IMO 9419565
|
158,368 | 2013 |
2.8
|
A |
| 308 |
ECO WEST COAST
IMO 9902811
|
157,668 | 2021 |
2.8
|
A |
| 310 |
EPHESOS
IMO 9607423
|
164,732 | 2012 |
2.8
|
A |
| 312 |
FRONT CRUISER
IMO 9797230
|
157,215 | 2020 |
2.8
|
A |
| 311 |
OLYMPIC FRIENDSHIP
IMO 9745251
|
158,885 | 2017 |
2.8
|
A |
| 313 |
ECO MALIBU
IMO 9902823
|
157,668 | 2021 |
2.8
|
A |
| 318 |
MINERVA KALYPSO
IMO 9785225
|
159,055 | 2017 |
2.8
|
A |
| 317 |
OTTOMAN TENACITY
IMO 9590682
|
149,999 | 2012 |
2.8
|
A |
| 316 |
TAMARA
IMO 9600889
|
157,016 | 2015 |
2.8
|
A |
| 315 |
SOFIA
IMO 9461764
|
164,716 | 2010 |
2.8
|
A |
| 314 |
SATURN MOON
IMO 9814430
|
158,000 | 2020 |
2.8
|
A |
| 319 |
SEAWAYS RED
IMO 9596973
|
159,068 | 2012 |
2.8
|
A |
| 323 |
NANTUCKET
IMO 9600865
|
157,000 | 2014 |
2.8
|
A |
| 322 |
VICTORY VENTURE
IMO 9773040
|
114,456 | 2017 |
2.8
|
A |
| 321 |
EMERALDWAY
IMO 9907653
|
158,362 | 2020 |
2.8
|
A |
| 320 |
BEIJING SPIRIT
IMO 9418597
|
156,493 | 2010 |
2.8
|
A |
| 324 |
SEAWAYS SABINE
IMO 9594755
|
158,493 | 2012 |
2.8
|
A |
| 326 |
FONTANA
IMO 9792541
|
159,430 | 2017 |
2.8
|
A |
| 328 |
PSARA I
IMO 9772333
|
156,975 | 2017 |
2.8
|
A |
| 327 |
MARLIN SANTORINI
IMO 9835836
|
156,587 | 2019 |
2.8
|
A |
| 325 |
SEAWAYS FRIO
IMO 9596985
|
159,000 | 2012 |
2.8
|
A |
| 330 |
JARNAIN
IMO 9823546
|
114,831 | 2021 |
2.8
|
A |
| 329 |
SEAWAYS HATTERAS
IMO 9730414
|
158,432 | 2017 |
2.8
|
A |
| 333 |
NORDIC HAWK
IMO 9749491
|
158,594 | 2016 |
2.8
|
A |
| 332 |
MILOS
IMO 9746619
|
157,525 | 2016 |
2.8
|
A |
| 331 |
NORDIC BREEZE
IMO 9588445
|
158,597 | 2011 |
2.8
|
A |
| 334 |
OCEAN LOYALTY
IMO 9375238
|
299,991 | 2010 |
2.8
|
A |
| 335 |
KANARIS 21
IMO 9889942
|
156,921 | 2021 |
2.8
|
A |
| 336 |
TAHITI
IMO 9600877
|
157,022 | 2014 |
2.8
|
A |
| 338 |
ANTIGUA I
IMO 9753363
|
157,392 | 2016 |
2.9
|
A |
| 337 |
PLUTO MOON
IMO 9784025
|
150,000 | 2019 |
2.9
|
A |
| 340 |
ENERGY TRIUMPH
IMO 9817614
|
157,470 | 2018 |
2.9
|
A |
| 339 |
OCEANIA
IMO 9905344
|
163,085 | 2022 |
2.9
|
A |
| 345 |
YASA POLARIS
IMO 9907457
|
158,224 | 2022 |
2.9
|
A |
| 346 |
CAP THEODORA
IMO 9380740
|
158,819 | 2008 |
2.9
|
A |
| 344 |
LOVELY LADY
IMO 9960978
|
115,322 | 2023 |
2.9
|
A |
| 347 |
DIAMONDWAY
IMO 9742895
|
154,966 | 2016 |
2.9
|
A |
| 343 |
MARAN SOLON
IMO 9881691
|
157,946 | 2021 |
2.9
|
A |
| 342 |
ADVANTAGE SWEET
IMO 9587192
|
159,058 | 2012 |
2.9
|
A |
| 341 |
NEPTUNE MOON
IMO 9784013
|
150,000 | 2019 |
2.9
|
A |
| 349 |
NISSOS SIKINOS
IMO 9884033
|
157,447 | 2020 |
2.9
|
A |
| 348 |
CAPTAIN MICHAEL
IMO 9531480
|
157,648 | 2012 |
2.9
|
A |
| 350 |
FRONT SPARTA
IMO 9847114
|
158,006 | 2019 |
2.9
|
A |
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.