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 |
|---|---|---|---|---|---|
| 302 |
STENA IMPERIAL
IMO 9667485
|
49,750 | 2015 |
5.8
|
B |
| 301 |
FPMC 29
IMO 9581667
|
50,545 | 2011 |
5.8
|
B |
| 305 |
MTM BIG APPLE
IMO 9774563
|
35,957 | 2018 |
5.8
|
B |
| 304 |
HAFNIA AXINITE
IMO 9719771
|
38,506 | 2015 |
5.8
|
B |
| 303 |
TORM ALEXANDRA
IMO 9466001
|
49,999 | 2010 |
5.8
|
B |
| 306 |
SV WAKILI
IMO 9590711
|
51,441 | 2012 |
5.8
|
B |
| 307 |
SEAWAYS MADELEINE
IMO 9380518
|
49,999 | 2008 |
5.8
|
B |
| 309 |
CL PEARL BUCK
IMO 9943334
|
49,315 | 2023 |
5.8
|
B |
| 308 |
ARDMORE PURPOSE
IMO 9859208
|
50,192 | 2020 |
5.8
|
B |
| 310 |
GALLOP
IMO 9799678
|
37,250 | 2019 |
5.8
|
B |
| 311 |
TORM DUBAI
IMO 9681390
|
49,990 | 2012 |
5.8
|
B |
| 313 |
CHAMPION ISTRA
IMO 9489209
|
51,655 | 2012 |
5.8
|
B |
| 312 |
MIA GRACE
IMO 9681132
|
49,990 | 2014 |
5.8
|
B |
| 315 |
PANTERA
IMO 9301914
|
49,999 | 2007 |
5.8
|
B |
| 314 |
PEACE ONE
IMO 9428334
|
49,867 | 2009 |
5.8
|
B |
| 317 |
CHEMROAD KAIA
IMO 1037684
|
35,769 | 2025 |
5.8
|
B |
| 316 |
ARDMORE SEAVANTAGE
IMO 9637076
|
47,790 | 2014 |
5.8
|
B |
| 318 |
BRAVE OCEAN
IMO 9359363
|
46,105 | 2010 |
5.9
|
B |
| 319 |
TP ENDEAVOUR
IMO 9835056
|
49,999 | 2020 |
5.9
|
B |
| 321 |
OCEAN PRINCESS I
IMO 9391517
|
50,549 | 2008 |
5.9
|
B |
| 320 |
JAL KAILASH
IMO 1013999
|
50,658 | 2025 |
5.9
|
B |
| 324 |
HAFNIA ARONALDO
IMO 9711561
|
38,506 | 2015 |
5.9
|
B |
| 323 |
DEGU
IMO 9985849
|
49,999 | 2025 |
5.9
|
B |
| 322 |
PACIFIC BLUE
IMO 9867798
|
49,995 | 2020 |
5.9
|
B |
| 325 |
FATIMAH
IMO 9917830
|
55,202 | 2022 |
5.9
|
B |
| 326 |
HAFNIA AMAZONITE
IMO 9719769
|
37,596 | 2015 |
5.9
|
B |
| 327 |
SEAWAYS MIRAGE
IMO 9387138
|
51,476 | 2009 |
5.9
|
B |
| 330 |
WECO MADELEINE
IMO 9693824
|
49,708 | 2016 |
5.9
|
B |
| 329 |
THERESA DUA
IMO 9919723
|
49,449 | 2023 |
5.9
|
B |
| 328 |
CABO NEGRO II
IMO 9317248
|
47,236 | 2006 |
5.9
|
B |
| 331 |
GREAT WHITE
IMO 9392793
|
50,004 | 2009 |
5.9
|
B |
| 332 |
NORD MARVEL
IMO 9877561
|
50,185 | 2020 |
5.9
|
B |
| 333 |
VESTA
IMO 9629938
|
49,990 | 2012 |
5.9
|
B |
| 334 |
CHAMPION CONTEST
IMO 9272199
|
47,171 | 2005 |
6.0
|
B |
| 335 |
CHASE OCEAN
IMO 9290660
|
46,959 | 2006 |
6.0
|
B |
| 336 |
IONIAN FIGHTER
IMO 9422225
|
46,639 | 2010 |
6.0
|
B |
| 339 |
AINAZI
IMO 9323405
|
52,606 | 2008 |
6.0
|
B |
| 338 |
CHEMROAD SIRIUS
IMO 9757979
|
35,757 | 2018 |
6.0
|
B |
| 337 |
CS ZHE JIANG
IMO 9899478
|
47,497 | 2022 |
6.0
|
B |
| 340 |
HAFNIA TANZANITE
IMO 9753703
|
49,478 | 2014 |
6.0
|
B |
| 341 |
TORM LILLY
IMO 9392470
|
53,116 | 2009 |
6.0
|
B |
| 342 |
JOSE PROGRESS
IMO 9392391
|
47,018 | 2009 |
6.0
|
B |
| 343 |
TORM ALLEGRO
IMO 9484912
|
46,184 | 2012 |
6.0
|
B |
| 346 |
ARDMORE EXPORTER
IMO 9654775
|
49,526 | 2014 |
6.0
|
B |
| 345 |
ETERNITY
IMO 1045693
|
50,313 | 2025 |
6.0
|
B |
| 344 |
STENA IMAGE
IMO 9667473
|
49,719 | 2015 |
6.0
|
B |
| 347 |
TORM AUSTRALIA
IMO 9443140
|
49,999 | 2011 |
6.0
|
B |
| 350 |
MOSTAR
IMO 9313474
|
51,274 | 2007 |
6.0
|
B |
| 349 |
LUCKY SAILOR
IMO 9464352
|
37,596 | 2009 |
6.0
|
B |
| 348 |
HAFNIA ANDESINE
IMO 9711559
|
38,506 | 2015 |
6.0
|
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.