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 |
|---|---|---|---|---|---|
| 249 |
MINERVA KALLISTO
IMO 9853008
|
113,000 | 2019 |
2.8
|
A |
| 254 |
ORINOCCO
IMO 9302994
|
150,296 | 2007 |
2.8
|
A |
| 253 |
MILOS
IMO 9746619
|
157,525 | 2016 |
2.8
|
A |
| 252 |
TORM HERMIA
IMO 9797993
|
114,939 | 2018 |
2.8
|
A |
| 256 |
NAVE DORADO
IMO 9993884
|
115,761 | 2025 |
2.8
|
A |
| 255 |
MINERVA ALEXANDRA
IMO 9892999
|
115,484 | 2021 |
2.8
|
A |
| 260 |
DELTA OCEAN
IMO 9408475
|
157,444 | 2010 |
2.8
|
A |
| 259 |
LOS ANGELES SPIRIT
IMO 9318072
|
159,233 | 2007 |
2.8
|
A |
| 258 |
ECO OCEANO CA
IMO 9794020
|
157,285 | 2022 |
2.8
|
A |
| 257 |
YUAN HE WAN
IMO 9845996
|
113,642 | 2020 |
2.8
|
A |
| 261 |
CAPTAIN LYRISTIS
IMO 9877183
|
158,081 | 2021 |
2.8
|
A |
| 262 |
MARLIN SARDINIA
IMO 9835862
|
156,606 | 2019 |
2.8
|
A |
| 263 |
MARAN SOLON
IMO 9881691
|
157,946 | 2021 |
2.8
|
A |
| 265 |
MELTEMI I
IMO 9298741
|
163,759 | 2006 |
2.8
|
A |
| 264 |
EAGLE SAN DIEGO
IMO 9594834
|
157,849 | 2012 |
2.8
|
A |
| 266 |
SEA CORAL
IMO 9920708
|
157,104 | 2020 |
2.8
|
A |
| 268 |
MINERVA KALYPSO
IMO 9785225
|
159,055 | 2017 |
2.8
|
A |
| 267 |
FRONT SINGAPORE
IMO 9832248
|
158,006 | 2019 |
2.8
|
A |
| 270 |
MARATHI
IMO 9772357
|
158,000 | 2018 |
2.8
|
A |
| 269 |
AEGEAN VISION
IMO 9645437
|
158,888 | 2015 |
2.8
|
A |
| 273 |
MONTE URQUIOLA
IMO 9803273
|
156,331 | 2019 |
2.8
|
A |
| 272 |
EUROPE I
IMO 9905332
|
163,136 | 2022 |
2.8
|
A |
| 271 |
MARAN HELEN
IMO 9779381
|
156,458 | 2017 |
2.8
|
A |
| 275 |
GH HOLIDAY
IMO 9761528
|
157,543 | 2014 |
2.8
|
A |
| 274 |
KAPODISTRIAS 21
IMO 9886639
|
158,081 | 2021 |
2.8
|
A |
| 276 |
SIKINOS I
IMO 9800269
|
157,007 | 2018 |
2.8
|
A |
| 277 |
EAGLE BARCELONA
IMO 9795048
|
113,400 | 2015 |
2.8
|
A |
| 279 |
EXPLORER
IMO 9312133
|
163,759 | 2006 |
2.8
|
A |
| 281 |
TAVISTOCK SQUARE
IMO 9784001
|
114,364 | 2019 |
2.8
|
A |
| 278 |
TAMARA
IMO 9600889
|
157,016 | 2015 |
2.8
|
A |
| 280 |
SEAWAYS RED
IMO 9596973
|
159,068 | 2012 |
2.8
|
A |
| 284 |
AEGEAN UNITY
IMO 9745237
|
158,932 | 2014 |
2.8
|
A |
| 283 |
UNIVERSAL PARTNER
IMO 9837614
|
299,981 | 2019 |
2.8
|
A |
| 282 |
ATLANTIC QUEEN
IMO 9899375
|
156,828 | 2021 |
2.8
|
A |
| 286 |
AMALIA M
IMO 9924003
|
157,010 | 2022 |
2.9
|
A |
| 285 |
BAKER SPIRIT
IMO 9408073
|
156,928 | 2009 |
2.9
|
A |
| 287 |
FRONT SAMARA
IMO 9845130
|
158,018 | 2017 |
2.9
|
A |
| 288 |
SFL TRINITY
IMO 9799862
|
114,900 | 2017 |
2.9
|
A |
| 290 |
APOLYTARES
IMO 9419474
|
316,679 | 2009 |
2.9
|
A |
| 289 |
ELISABETH MAERSK
IMO 9682980
|
158,277 | 2017 |
2.9
|
A |
| 291 |
RUNNER
IMO 9749518
|
158,594 | 2014 |
2.9
|
A |
| 293 |
MARFA
IMO 9773478
|
159,512 | 2017 |
2.9
|
A |
| 292 |
APACHE
IMO 9749489
|
158,594 | 2016 |
2.9
|
A |
| 299 |
FRONT CROWN
IMO 9759757
|
157,460 | 2016 |
2.9
|
A |
| 298 |
CARINA VOYAGER
IMO 9897834
|
113,764 | 2021 |
2.9
|
A |
| 297 |
NORDIC GALAXY
IMO 9742895
|
154,966 | 2016 |
2.9
|
A |
| 296 |
FRONT SHANGHAI
IMO 9832262
|
158,006 | 2019 |
2.9
|
A |
| 295 |
STENA SUPERIOR
IMO 9579030
|
159,000 | 2011 |
2.9
|
A |
| 294 |
JAG LAADKI
IMO 9461764
|
164,716 | 2010 |
2.9
|
A |
| 300 |
SILVERWAY
IMO 9742912
|
157,781 | 2017 |
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 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.