Most Emission-Efficient LNG Carriers
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 |
|---|---|---|---|---|---|
| 201 |
MOL HESTIA
IMO 9885996
|
93,798 | 2021 |
5.9
|
C |
| 202 |
PALU LNG
IMO 9636735
|
89,874 | 2014 |
5.9
|
C |
| 203 |
LNG ADVENTURE
IMO 9870159
|
88,817 | 2021 |
5.9
|
C |
| 204 |
DIAMOND GAS METROPOLIS
IMO 9862487
|
89,846 | 2018 |
6.0
|
C |
| 205 |
PAN AMERICAS
IMO 9750232
|
88,425 | 2018 |
6.0
|
C |
| 206 |
LNG SAKURA
IMO 9774135
|
82,137 | 2018 |
6.0
|
C |
| 207 |
LNG DUBHE
IMO 9834296
|
91,587 | 2019 |
6.0
|
C |
| 208 |
MARAN GAS KIMOLOS
IMO 9956393
|
81,200 | 2021 |
6.0
|
C |
| 209 |
BRITISH LISTENER
IMO 9766566
|
94,494 | 2019 |
6.0
|
C |
| 210 |
PAN EUROPE
IMO 9750244
|
88,407 | 2018 |
6.0
|
C |
| 211 |
GASLOG GREECE
IMO 9687019
|
94,400 | 2016 |
6.1
|
C |
| 212 |
FLEX ARTEMIS
IMO 9851634
|
95,450 | 2020 |
6.1
|
C |
| 213 |
MARVEL FALCON
IMO 9760768
|
85,000 | 2018 |
6.1
|
C |
| 214 |
MARAN GAS VERGINA
IMO 9732369
|
96,000 | 2016 |
6.2
|
C |
| 215 |
ORION SPIRIT
IMO 9956587
|
87,886 | 2021 |
6.2
|
C |
| 216 |
BRITISH MENTOR
IMO 9766578
|
94,528 | 2019 |
6.2
|
C |
| 217 |
MARVEL HAWK
IMO 9760770
|
85,000 | 2018 |
6.2
|
C |
| 218 |
BW PAVILION ARANTHERA
IMO 9850678
|
90,400 | 2020 |
6.2
|
C |
| 219 |
BRITISH CONTRIBUTOR
IMO 9766554
|
94,558 | 2018 |
6.2
|
C |
| 220 |
ELISA LARUS
IMO 9852975
|
95,418 | 2020 |
6.2
|
C |
| 221 |
COOL VOYAGER
IMO 9636785
|
81,890 | 2013 |
6.2
|
C |
| 222 |
KOOL FROST
IMO 9655042
|
82,005 | 2014 |
6.2
|
C |
| 223 |
LNG PORT HARCOURT II
IMO 9690157
|
87,139 | 2015 |
6.2
|
C |
| 224 |
MARAN GAS SPARTA
IMO 9650042
|
90,392 | 2015 |
6.2
|
C |
| 225 |
BW PAVILION VANDA
IMO 9640437
|
86,401 | 2015 |
6.3
|
C |
| 226 |
KINISIS
IMO 9785158
|
95,673 | 2018 |
6.3
|
C |
| 227 |
SEAPEAK OAK
IMO 9681699
|
95,412 | 2016 |
6.3
|
C |
| 228 |
ENERGY UNIVERSE
IMO 9758844
|
88,700 | 2019 |
6.3
|
C |
| 229 |
MARVEL CRANE
IMO 9770438
|
97,794 | 2015 |
6.3
|
C |
| 230 |
CLEAN PLANET
IMO 9637507
|
89,848 | 2014 |
6.3
|
D |
| 231 |
GASLOG GENEVA
IMO 9707508
|
94,400 | 2013 |
6.4
|
D |
| 232 |
WILPRIDE
IMO 9627966
|
87,677 | 2013 |
6.4
|
D |
| 233 |
COOL EXPLORER
IMO 9640023
|
81,893 | 2015 |
6.4
|
D |
| 234 |
RIOJA KNUTSEN
IMO 9721736
|
92,782 | 2016 |
6.4
|
D |
| 235 |
BRITISH ACHIEVER
IMO 9766542
|
94,303 | 2018 |
6.5
|
D |
| 236 |
CASTILLO DE CALDELAS
IMO 9742819
|
93,241 | 2018 |
6.5
|
D |
| 237 |
CLEAN OCEAN
IMO 9637492
|
89,956 | 2014 |
6.5
|
D |
| 238 |
FLEX ENDEAVOUR
IMO 9762261
|
85,000 | 2018 |
6.5
|
D |
| 239 |
LNG JUNO
IMO 9774628
|
85,000 | 2018 |
6.5
|
D |
| 240 |
COOL RUNNER
IMO 9636797
|
81,893 | 2014 |
6.5
|
D |
| 241 |
MARAN GAS PERICLES
IMO 9709489
|
92,776 | 2016 |
6.5
|
D |
| 242 |
NORTH OCEAN
IMO 9958315
|
91,430 | 2024 |
6.5
|
D |
| 243 |
GRACE FREESIA
IMO 9903920
|
89,789 | 2019 |
6.5
|
D |
| 244 |
CLEAN VISION
IMO 9655456
|
89,863 | 2016 |
6.6
|
D |
| 245 |
ENERGY GLORY
IMO 9752565
|
88,677 | 2019 |
6.6
|
D |
| 246 |
KOOL ICE
IMO 9637325
|
81,534 | 2015 |
6.6
|
D |
| 247 |
LA MANCHA KNUTSEN
IMO 9721724
|
92,802 | 2016 |
6.7
|
D |
| 248 |
KONGTONG
IMO 9958664
|
91,682 | 2025 |
6.7
|
D |
| 249 |
MARAN GAS LETO
IMO 9682576
|
92,846 | 2016 |
6.7
|
D |
| 250 |
SEVILLA KNUTSEN
IMO 9414632
|
100,002 | 2010 |
6.7
|
D |
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.