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 |
|---|---|---|---|---|---|
| 1 |
SEA WOLF I
IMO 9540807
|
49,936 | 2011 |
3.5
|
A |
| 2 |
DELOS C
IMO 1058341
|
49,996 | 2025 |
3.7
|
A |
| 3 |
MANDALA
IMO 9299135
|
65,125 | 2006 |
3.8
|
A |
| 4 |
MH IBUKI
IMO 9994711
|
49,948 | 2025 |
3.9
|
A |
| 5 |
LAGERI
IMO 1021934
|
49,996 | 2026 |
3.9
|
A |
| 6 |
HAFNIA GUANGZHOU
IMO 9856622
|
74,999 | 2019 |
3.9
|
A |
| 7 |
SILVER MOON
IMO 1018872
|
49,986 | 2025 |
4.0
|
A |
| 8 |
VICTORIA BAY
IMO 9974981
|
50,000 | 2024 |
4.0
|
A |
| 9 |
BANTRY BAY
IMO 9967249
|
49,999 | 2023 |
4.1
|
A |
| 10 |
MOSSEL BAY
IMO 9970375
|
49,999 | 2024 |
4.1
|
A |
| 12 |
MUSTANG
IMO 9995442
|
50,539 | 2025 |
4.1
|
A |
| 13 |
KALK BAY
IMO 9970363
|
49,999 | 2022 |
4.1
|
A |
| 11 |
ELAIA
IMO 9798363
|
49,996 | 2019 |
4.1
|
A |
| 14 |
JAL PRERANA
IMO 1013987
|
50,640 | 2025 |
4.1
|
A |
| 15 |
ISLA DE BIOKO
IMO 9767235
|
51,609 | 2016 |
4.2
|
A |
| 16 |
TORM INTEGRITY
IMO 9602710
|
73,811 | 2010 |
4.2
|
A |
| 17 |
DEE4 NERIUM
IMO 9929821
|
49,990 | 2022 |
4.2
|
A |
| 18 |
TORM DORIS
IMO 9683398
|
49,680 | 2015 |
4.2
|
A |
| 19 |
ATLANTIC SUNSHINE
IMO 9993810
|
50,000 | 2024 |
4.2
|
A |
| 22 |
TORM DURGA
IMO 9682382
|
49,680 | 2014 |
4.2
|
A |
| 21 |
TORM DAGMAR
IMO 9702209
|
49,999 | 2015 |
4.2
|
A |
| 20 |
TORM SUBLIME
IMO 9854789
|
49,974 | 2019 |
4.2
|
A |
| 23 |
DEE4 KASTANIA
IMO 9933638
|
49,999 | 2020 |
4.2
|
A |
| 24 |
TORM DAPHNE
IMO 9692313
|
49,746 | 2015 |
4.2
|
A |
| 25 |
ARDMORE PURSUIT
IMO 9732931
|
50,000 | 2017 |
4.2
|
A |
| 26 |
MUGELLO
IMO 1030040
|
74,976 | 2025 |
4.2
|
A |
| 27 |
STI GALLANTRY
IMO 9712876
|
109,999 | 2016 |
4.2
|
A |
| 28 |
TORM DIANA
IMO 9702223
|
49,999 | 2013 |
4.3
|
A |
| 29 |
MH NORIKURA
IMO 9994694
|
49,999 | 2025 |
4.3
|
A |
| 30 |
PS IMABARI
IMO 9908504
|
52,838 | 2022 |
4.3
|
A |
| 32 |
STENA PRO MARINE
IMO 9899739
|
49,990 | 2022 |
4.3
|
A |
| 31 |
DEE4 JUNIPER
IMO 9930923
|
49,999 | 2020 |
4.3
|
A |
| 33 |
TORM SOVEREIGN
IMO 9797723
|
49,999 | 2015 |
4.3
|
A |
| 34 |
PHILOXENIA
IMO 9857250
|
49,999 | 2019 |
4.3
|
A |
| 35 |
DEE4 ILEX
IMO 9922093
|
49,999 | 2020 |
4.3
|
A |
| 37 |
TORM DAMINI
IMO 9682370
|
49,746 | 2012 |
4.3
|
A |
| 36 |
AMIRA
IMO 9917842
|
55,202 | 2022 |
4.3
|
A |
| 38 |
SEYMOUR SUN
IMO 9911501
|
49,999 | 2022 |
4.4
|
A |
| 39 |
PALAWAN STAR
IMO 9401233
|
73,796 | 2008 |
4.4
|
A |
| 40 |
TORM BIRGITTE
IMO 9664720
|
49,995 | 2012 |
4.4
|
A |
| 41 |
SEAMERIT
IMO 1014034
|
50,498 | 2025 |
4.4
|
A |
| 42 |
STENA PROSPEROUS
IMO 9923750
|
49,990 | 2022 |
4.4
|
A |
| 45 |
IONIAN STAR
IMO 9828895
|
50,506 | 2019 |
4.4
|
A |
| 44 |
TORM DULCE
IMO 9682394
|
49,746 | 2014 |
4.4
|
A |
| 43 |
AGISILAOS
IMO 9953418
|
50,113 | 2023 |
4.4
|
A |
| 46 |
AGIOS NIKOLAOS
IMO 9820283
|
49,988 | 2018 |
4.4
|
A |
| 47 |
TORM DEBORAH
IMO 9683386
|
49,680 | 2015 |
4.4
|
A |
| 48 |
AGIOI FANENDES
IMO 9798375
|
49,996 | 2019 |
4.5
|
A |
| 50 |
MINDORO STAR
IMO 9441207
|
73,677 | 2009 |
4.5
|
A |
| 49 |
EUROSAILOR
IMO 9895915
|
49,999 | 2021 |
4.5
|
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.