Most Emission-Efficient Chemical 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 |
|---|---|---|---|---|---|
| 250 |
YASA VEGA
IMO 9888352
|
50,215 | 2021 |
5.5
|
A |
| 255 |
HAFNIA VALENTINO
IMO 9692246
|
49,126 | 2015 |
5.6
|
A |
| 254 |
GOUSEA
IMO 9692155
|
49,573 | 2015 |
5.6
|
A |
| 253 |
YASA FLAMINGO
IMO 9857236
|
50,215 | 2019 |
5.6
|
A |
| 256 |
STI MYSTERY
IMO 9829461
|
49,999 | 2019 |
5.6
|
A |
| 252 |
ELKA ASTIR
IMO 9705885
|
49,990 | 2015 |
5.6
|
A |
| 257 |
SEA ELEPHANT
IMO 9853254
|
49,929 | 2019 |
5.6
|
A |
| 258 |
AUGENSTERN
IMO 9939577
|
49,600 | 2021 |
5.6
|
A |
| 259 |
OAKTREE
IMO 9384021
|
51,257 | 2008 |
5.6
|
A |
| 260 |
ALPINE EAGLE
IMO 9366275
|
51,542 | 2008 |
5.6
|
A |
| 261 |
CHEMROAD AQUA
IMO 9790610
|
35,678 | 2018 |
5.6
|
A |
| 263 |
ARDMORE SEAHAWK
IMO 9708239
|
49,999 | 2015 |
5.6
|
A |
| 264 |
ION M
IMO 9864344
|
49,999 | 2019 |
5.6
|
A |
| 262 |
PACIFIC SARAH
IMO 9772034
|
74,242 | 2017 |
5.6
|
A |
| 265 |
CL EMILY BRONTE
IMO 9943322
|
49,348 | 2023 |
5.6
|
A |
| 268 |
LARGO AURORA
IMO 1034735
|
49,805 | 2025 |
5.6
|
A |
| 267 |
HAFNIA AQUAMARINE
IMO 9711573
|
38,506 | 2013 |
5.6
|
A |
| 266 |
MARLIN AMETRINE
IMO 9697234
|
49,999 | 2015 |
5.6
|
A |
| 269 |
HAFNIA LEO
IMO 9476824
|
49,999 | 2013 |
5.6
|
A |
| 270 |
HAFNIA ALMANDINE
IMO 9714068
|
38,506 | 2015 |
5.6
|
A |
| 273 |
CHAMPION CORNELIA
IMO 9447744
|
51,551 | 2010 |
5.7
|
A |
| 272 |
MARITIME TRANQUILITY
IMO 9848338
|
49,999 | 2020 |
5.7
|
A |
| 271 |
FALKANGER
IMO 9387695
|
46,239 | 2009 |
5.7
|
A |
| 274 |
NORD VOLANTE
IMO 9944144
|
50,378 | 2023 |
5.7
|
A |
| 275 |
STENA IMMORTAL
IMO 9685475
|
49,647 | 2016 |
5.7
|
A |
| 277 |
UZAVA
IMO 9323388
|
52,650 | 2008 |
5.7
|
A |
| 276 |
TORM ASLAUG
IMO 9465978
|
49,999 | 2010 |
5.7
|
A |
| 278 |
ST HELEN
IMO 9934151
|
50,226 | 2022 |
5.7
|
A |
| 280 |
NAVIG8 GRATITUDE
IMO 9853242
|
49,772 | 2019 |
5.7
|
A |
| 279 |
AEGEAN C
IMO 1019773
|
50,159 | 2025 |
5.7
|
A |
| 282 |
STOLT GLORY
IMO 9311012
|
33,929 | 2005 |
5.7
|
A |
| 281 |
VELOCITY
IMO 1045710
|
49,998 | 2025 |
5.7
|
A |
| 284 |
LARGO EVOLUTION
IMO 9687942
|
49,750 | 2015 |
5.7
|
A |
| 283 |
HAFNIA DAISY
IMO 9709788
|
49,899 | 2016 |
5.7
|
A |
| 285 |
SEAWAYS POLARIS
IMO 9392779
|
49,999 | 2009 |
5.7
|
A |
| 286 |
NORD ELEGANCE
IMO 9870707
|
50,415 | 2020 |
5.7
|
A |
| 287 |
ENSEMBLE
IMO 9749453
|
35,058 | 2017 |
5.7
|
A |
| 288 |
YASA ALBATROSS
IMO 9857212
|
50,215 | 2019 |
5.7
|
B |
| 290 |
NAVIG8 EXCELLENCE
IMO 9976886
|
49,160 | 2025 |
5.7
|
B |
| 289 |
RIVIERA
IMO 9384019
|
51,218 | 2008 |
5.7
|
B |
| 291 |
SEAWAYS MUSE
IMO 9374301
|
51,498 | 2009 |
5.7
|
B |
| 293 |
SOLAR SALLY
IMO 9898498
|
49,314 | 2021 |
5.7
|
B |
| 292 |
SEA FRACTUS
IMO 9724609
|
45,999 | 2016 |
5.7
|
B |
| 294 |
TORM LOUISE
IMO 9392482
|
53,049 | 2009 |
5.8
|
B |
| 299 |
TORM LOTTE
IMO 9392468
|
52,996 | 2009 |
5.8
|
B |
| 298 |
ARDMORE ENCOUNTER
IMO 9654579
|
49,477 | 2014 |
5.8
|
B |
| 297 |
HAFNIA AMETRINE
IMO 9714513
|
38,506 | 2015 |
5.8
|
B |
| 296 |
GOLDEN VOYAGER
IMO 9939058
|
49,999 | 2022 |
5.8
|
B |
| 295 |
HAFNIA TOURMALINE
IMO 9753698
|
49,513 | 2014 |
5.8
|
B |
| 300 |
STENA IMPERIAL
IMO 9667485
|
49,750 | 2015 |
5.8
|
B |
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.