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 |
|---|---|---|---|---|---|
| 801 |
SFL BONAIRE
IMO 9919773
|
33,338 | 2023 |
9.0
|
C |
| 802 |
ARS ET LABOUR
IMO 9396385
|
40,416 | 2008 |
9.0
|
C |
| 803 |
BOW EXPLORER
IMO 9828211
|
38,235 | 2020 |
9.0
|
C |
| 804 |
SELANGOR PARK
IMO 1016185
|
19,988 | 2025 |
9.0
|
C |
| 805 |
ORIENTAL SAKURA
IMO 9743746
|
16,090 | 2015 |
9.1
|
C |
| 806 |
BOW LYNX
IMO 9989194
|
25,914 | 2024 |
9.1
|
C |
| 807 |
ORIENTAL VIOLA
IMO 9824928
|
16,293 | 2020 |
9.1
|
C |
| 808 |
STOLT MERCURY
IMO 9739329
|
27,578 | 2017 |
9.1
|
C |
| 809 |
XT DOLPHIN
IMO 9672478
|
27,259 | 2013 |
9.1
|
C |
| 810 |
SEYCHELLES PROGRESS
IMO 9298181
|
37,558 | 2005 |
9.1
|
C |
| 811 |
ALLEGRA
IMO 9436707
|
40,408 | 2006 |
9.1
|
C |
| 812 |
EASTERLY AS OMARIA
IMO 9363819
|
19,973 | 2007 |
9.1
|
C |
| 813 |
PEONIA
IMO 9313436
|
28,987 | 2005 |
9.1
|
C |
| 814 |
WAN HE
IMO 9248461
|
24,404 | 2002 |
9.1
|
C |
| 815 |
LIPARI M
IMO 9587817
|
37,583 | 2011 |
9.1
|
C |
| 816 |
HONOR GALAXY
IMO 9860207
|
21,028 | 2019 |
9.2
|
C |
| 817 |
NINA AN
IMO 9451733
|
40,399 | 2010 |
9.2
|
C |
| 818 |
ATLAS STAR
IMO 9376828
|
38,289 | 2008 |
9.2
|
C |
| 819 |
DIDIMON
IMO 9288772
|
37,432 | 2005 |
9.2
|
C |
| 820 |
ICHESIA M
IMO 9436678
|
40,429 | 2009 |
9.2
|
C |
| 821 |
MARIA M
IMO 9301885
|
34,999 | 2006 |
9.2
|
C |
| 822 |
STOLT ZULU
IMO 9351531
|
25,197 | 2006 |
9.2
|
C |
| 823 |
MTM SAVANNAH
IMO 9726750
|
22,430 | 2015 |
9.2
|
C |
| 824 |
MINERVA TYCHI
IMO 9723291
|
39,070 | 2016 |
9.2
|
C |
| 825 |
ARDMORE CHIPPEWA
IMO 9707871
|
25,217 | 2015 |
9.2
|
C |
| 826 |
ORIENTAL COSMOS
IMO 9800049
|
16,296 | 2015 |
9.2
|
C |
| 827 |
HAFNIA MALACCA
IMO 9725627
|
39,067 | 2015 |
9.2
|
C |
| 828 |
GINGA THRESHER
IMO 9829746
|
25,174 | 2019 |
9.2
|
C |
| 829 |
BOW CECIL
IMO 9143219
|
37,369 | 1998 |
9.2
|
C |
| 830 |
EASTERLY BIRDIE
IMO 9423724
|
25,399 | 2009 |
9.2
|
C |
| 831 |
STOLT SINCERITY
IMO 9680085
|
38,850 | 2016 |
9.2
|
C |
| 832 |
ARDMORE CHINOOK
IMO 9707869
|
25,233 | 2015 |
9.2
|
C |
| 833 |
FAIRCHEM PROTEA
IMO 9908346
|
19,959 | 2021 |
9.2
|
C |
| 834 |
STOLT INTEGRITY
IMO 9680097
|
38,853 | 2017 |
9.3
|
C |
| 835 |
AQUA RAY
IMO 9973676
|
21,950 | 2023 |
9.3
|
C |
| 836 |
LOUIS P
IMO 9749336
|
25,161 | 2016 |
9.3
|
C |
| 837 |
KRITI SAILOR
IMO 9335135
|
37,448 | 2007 |
9.3
|
C |
| 838 |
EK-STREAM
IMO 9808261
|
19,881 | 2018 |
9.3
|
C |
| 839 |
MIAMI
IMO 9304320
|
19,991 | 2005 |
9.3
|
C |
| 840 |
FORTE GALAXY
IMO 9817585
|
19,971 | 2018 |
9.3
|
C |
| 841 |
STOLT LOTUS
IMO 9617648
|
30,345 | 2014 |
9.3
|
C |
| 842 |
CHEM SELENIUM
IMO 9817509
|
19,998 | 2018 |
9.3
|
C |
| 843 |
CHEM ALTAMIRA
IMO 9705744
|
19,998 | 2015 |
9.3
|
C |
| 844 |
MH FUTURE
IMO 9986001
|
19,727 | 2024 |
9.3
|
C |
| 845 |
FAIRCHEM HAWK
IMO 9804813
|
19,956 | 2019 |
9.3
|
C |
| 846 |
LAVENDER RAY
IMO 9740794
|
19,994 | 2017 |
9.3
|
C |
| 847 |
PRABHU MIHIKAA
IMO 9674775
|
25,926 | 2014 |
9.3
|
C |
| 848 |
PVT CLARA
IMO 9442548
|
20,831 | 2009 |
9.3
|
C |
| 849 |
BASILIS L
IMO 9290505
|
37,371 | 2005 |
9.3
|
C |
| 850 |
LILAC RAY
IMO 9883481
|
21,028 | 2020 |
9.3
|
C |
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.