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 |
|---|---|---|---|---|---|
| 255 |
MARAN ORPHEUS
IMO 9868168
|
157,946 | 2020 |
2.6
|
A |
| 254 |
KAREKARE
IMO 9787986
|
159,638 | 2017 |
2.6
|
A |
| 253 |
KRITI ENERGY
IMO 9935636
|
156,740 | 2022 |
2.6
|
A |
| 252 |
FRONT SANTIAGO
IMO 9831842
|
157,270 | 2019 |
2.6
|
A |
| 251 |
EXPLORER
IMO 9312133
|
163,759 | 2006 |
2.6
|
A |
| 256 |
CRUDE ZEPHYRUS
IMO 9899375
|
156,828 | 2021 |
2.6
|
A |
| 257 |
LOIRE
IMO 9761516
|
157,463 | 2016 |
2.6
|
A |
| 258 |
YUAN BEI HAI
IMO 9843352
|
158,840 | 2021 |
2.6
|
A |
| 259 |
TAHOE SPIRIT
IMO 9427641
|
156,870 | 2010 |
2.6
|
A |
| 260 |
MARLIN SICILY
IMO 9835848
|
156,563 | 2017 |
2.6
|
A |
| 263 |
SEAVISION
IMO 9790971
|
158,480 | 2018 |
2.6
|
A |
| 262 |
NORDIC HUNTER
IMO 9921075
|
157,037 | 2022 |
2.6
|
A |
| 261 |
TOKYO SPIRIT
IMO 9296377
|
149,996 | 2006 |
2.6
|
A |
| 266 |
SONANGOL PORTO AMBOIM
IMO 9575577
|
157,638 | 2012 |
2.7
|
A |
| 265 |
SONANGOL RANGEL
IMO 9575541
|
157,755 | 2011 |
2.7
|
A |
| 264 |
FRONT SINGAPORE
IMO 9832248
|
158,006 | 2019 |
2.7
|
A |
| 267 |
EVA MAERSK
IMO 9682992
|
158,468 | 2017 |
2.7
|
A |
| 268 |
MONTE URQUIOLA
IMO 9803273
|
156,331 | 2019 |
2.7
|
A |
| 270 |
SEAGRACE
IMO 9934826
|
157,746 | 2022 |
2.7
|
A |
| 269 |
FRONT SILKEBORG
IMO 9832274
|
158,006 | 2019 |
2.7
|
A |
| 271 |
BALTIC LOYALTY
IMO 9411953
|
317,441 | 2010 |
2.7
|
A |
| 273 |
DHT EUROPE
IMO 9315159
|
317,713 | 2007 |
2.7
|
A |
| 272 |
SAMOS
IMO 9772345
|
158,000 | 2018 |
2.7
|
A |
| 274 |
MARAN HELIOS
IMO 9761358
|
156,458 | 2017 |
2.7
|
A |
| 277 |
DELTA OCEAN
IMO 9408475
|
157,444 | 2010 |
2.7
|
A |
| 276 |
VADELA
IMO 9996408
|
159,220 | 2024 |
2.7
|
A |
| 275 |
ELANDRA FALCON
IMO 9792486
|
157,553 | 2017 |
2.7
|
A |
| 278 |
FRONT CRYSTAL
IMO 9743186
|
157,409 | 2017 |
2.7
|
A |
| 279 |
NISSOS SIFNOS
IMO 9884045
|
157,447 | 2020 |
2.7
|
A |
| 282 |
MARLIN SOMERSET
IMO 9835850
|
156,620 | 2017 |
2.7
|
A |
| 281 |
NISSOS ANTIMILOS
IMO 9895226
|
157,447 | 2021 |
2.7
|
A |
| 280 |
ALDANA
IMO 9809368
|
156,670 | 2018 |
2.7
|
A |
| 284 |
FRONT SUEZ
IMO 9831830
|
157,270 | 2017 |
2.7
|
A |
| 283 |
BRISTOL
IMO 9941879
|
157,077 | 2024 |
2.7
|
A |
| 286 |
SPYROS
IMO 9877171
|
158,081 | 2020 |
2.7
|
A |
| 285 |
STENA SUNRISE
IMO 9592214
|
158,886 | 2013 |
2.7
|
A |
| 287 |
NORDIC SPACE
IMO 9748681
|
157,587 | 2017 |
2.7
|
A |
| 288 |
MARAN HERMES
IMO 9761346
|
156,458 | 2017 |
2.7
|
A |
| 289 |
EAGLE SAN DIEGO
IMO 9594834
|
157,849 | 2012 |
2.7
|
A |
| 292 |
ATLANTIC LOYALTY
IMO 9312509
|
307,284 | 2007 |
2.7
|
A |
| 291 |
OTIS
IMO 9408217
|
156,719 | 2010 |
2.7
|
A |
| 290 |
CARIBBEAN LOYALTY
IMO 9501150
|
316,373 | 2011 |
2.7
|
A |
| 294 |
SPEEDWAY
IMO 9749506
|
158,594 | 2017 |
2.7
|
A |
| 293 |
OTTOMAN COURTESY
IMO 9788708
|
152,544 | 2017 |
2.7
|
A |
| 300 |
YUAN DONG HAI
IMO 9843338
|
158,677 | 2020 |
2.7
|
A |
| 299 |
PLATA GLORY
IMO 9384590
|
297,974 | 2009 |
2.7
|
A |
| 298 |
AMALIA M
IMO 9924003
|
157,010 | 2022 |
2.7
|
A |
| 297 |
DELTA EURYDICE
IMO 9700706
|
157,031 | 2015 |
2.7
|
A |
| 296 |
MONTE UDALA
IMO 9785823
|
156,341 | 2018 |
2.7
|
A |
| 295 |
SOUNION
IMO 9312145
|
163,759 | 2006 |
2.7
|
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.