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 |
|---|---|---|---|---|---|
| 401 |
THERESA EMPAT
IMO 9931173
|
49,448 | 2023 |
6.3
|
B |
| 400 |
STOLT MAGNESIUM
IMO 9739317
|
27,605 | 2017 |
6.3
|
B |
| 404 |
NORD SUPERIOR
IMO 9692129
|
49,573 | 2015 |
6.3
|
B |
| 403 |
VELOS AQUARIUS
IMO 9381756
|
49,999 | 2008 |
6.3
|
B |
| 405 |
MINERVA JULIE
IMO 9380831
|
49,990 | 2008 |
6.3
|
B |
| 406 |
MRC SEDEF
IMO 9335032
|
45,951 | 2007 |
6.3
|
B |
| 407 |
OCIOS IOANNIS
IMO 9686986
|
49,997 | 2015 |
6.3
|
B |
| 409 |
BOW SUN
IMO 9197284
|
49,466 | 2003 |
6.3
|
B |
| 408 |
LILA KINGSTON
IMO 9380362
|
49,999 | 2007 |
6.3
|
B |
| 412 |
EVGENIA S
IMO 9388015
|
46,609 | 2008 |
6.3
|
B |
| 411 |
BOW SPRING
IMO 9215256
|
49,429 | 2004 |
6.3
|
B |
| 410 |
SOLAR SUZANNE
IMO 9877638
|
25,039 | 2020 |
6.3
|
B |
| 413 |
TORM AMORINA
IMO 9484895
|
46,184 | 2012 |
6.3
|
B |
| 414 |
GRAND ACE6
IMO 9375329
|
46,192 | 2007 |
6.3
|
B |
| 415 |
NAVIG8 GOAL
IMO 9853216
|
49,770 | 2019 |
6.3
|
B |
| 418 |
DUMBLEDORE
IMO 9325611
|
44,998 | 2007 |
6.3
|
B |
| 417 |
SEA GULL
IMO 9325855
|
33,849 | 2006 |
6.3
|
B |
| 416 |
PROTEUS
IMO 9864368
|
49,999 | 2018 |
6.3
|
B |
| 419 |
CHEMROAD POLARIS
IMO 9536923
|
35,923 | 2014 |
6.4
|
B |
| 420 |
BOW STAR
IMO 9197296
|
49,487 | 2004 |
6.4
|
B |
| 422 |
PACIFIC TAURUS
IMO 1034008
|
49,999 | 2025 |
6.4
|
B |
| 421 |
SALACGRIVA
IMO 9323390
|
52,620 | 2008 |
6.4
|
B |
| 425 |
MAGNATE
IMO 9461673
|
49,999 | 2011 |
6.4
|
B |
| 424 |
HAFNIA AMETHYST
IMO 9714501
|
38,506 | 2015 |
6.4
|
B |
| 423 |
FAIR BREEZE
IMO 9419723
|
49,900 | 2009 |
6.4
|
B |
| 426 |
BOW SEA
IMO 9215282
|
49,511 | 2006 |
6.4
|
B |
| 427 |
GREAT LAMDA
IMO 9873668
|
49,282 | 2020 |
6.4
|
B |
| 428 |
THERESA LIMA
IMO 9946130
|
49,448 | 2023 |
6.4
|
B |
| 430 |
CHEMROAD JUPITER
IMO 9932713
|
35,722 | 2022 |
6.4
|
B |
| 429 |
HAFNIA ADAMITE
IMO 9727546
|
38,506 | 2015 |
6.4
|
B |
| 431 |
CHEMROAD ORCHID
IMO 9790608
|
35,703 | 2019 |
6.4
|
B |
| 434 |
LEONORA VICTORY
IMO 9283784
|
46,889 | 2005 |
6.4
|
B |
| 433 |
ATHINA M
IMO 9644237
|
51,853 | 2011 |
6.4
|
B |
| 432 |
BOW SKY
IMO 9215268
|
49,479 | 2005 |
6.4
|
B |
| 436 |
CHAMPION PULA
IMO 9341146
|
46,927 | 2006 |
6.4
|
B |
| 435 |
BOW OLYMPUS
IMO 9818527
|
48,555 | 2019 |
6.4
|
B |
| 437 |
WENCHE VICTORY
IMO 9288825
|
47,210 | 2005 |
6.4
|
B |
| 438 |
GREAT THITA
IMO 9873670
|
49,276 | 2020 |
6.5
|
B |
| 439 |
HAFNIA AZURITE
IMO 9727560
|
38,506 | 2013 |
6.5
|
B |
| 440 |
CAPRI
IMO 9528392
|
50,895 | 2011 |
6.5
|
B |
| 441 |
BOW SIRIUS
IMO 9215294
|
49,539 | 2006 |
6.5
|
B |
| 442 |
SANTIAGO I
IMO 9730347
|
49,901 | 2022 |
6.5
|
B |
| 443 |
BOW PRECISION
IMO 9790646
|
35,155 | 2018 |
6.5
|
B |
| 446 |
PALMA
IMO 9384033
|
51,225 | 2008 |
6.5
|
B |
| 445 |
HARBIYE
IMO 9396787
|
50,553 | 2008 |
6.5
|
B |
| 444 |
PYXIS THETA
IMO 9657064
|
51,462 | 2013 |
6.5
|
B |
| 447 |
ARDMORE EXPLORER
IMO 9654581
|
49,494 | 2014 |
6.5
|
B |
| 448 |
FANTASIA
IMO 9378371
|
44,999 | 2009 |
6.5
|
B |
| 450 |
CRISTALLINA
IMO 1022718
|
49,999 | 2025 |
6.5
|
B |
| 449 |
ZEFYROS
IMO 9515917
|
50,155 | 2013 |
6.5
|
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.