Most Emission-Efficient Container Ships
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 (TEU) | Built | Carbon intensity — AER (g CO₂/dwt·nm) | Grade |
|---|---|---|---|---|---|
| 1 |
MSC CALAIS
IMO 9975600
|
131,034 | 2025 |
2.9
|
A |
| 2 |
CMA CGM ARGON
IMO 9996692
|
147,196 | 2025 |
3.1
|
A |
| 3 |
MSC MARIACRISTINA
IMO 9968279
|
16,000 TEU | 2025 |
3.2
|
A |
| 4 |
MSC SAVANNAH
IMO 9987342
|
16,000 TEU | 2025 |
3.2
|
A |
| 5 |
MSC GIOIA TAURO
IMO 9946738
|
13,115 TEU | 2025 |
3.3
|
A |
| 6 |
MSC MILAN
IMO 9964235
|
15,576 TEU | 2024 |
3.4
|
A |
| 7 |
MSC MARIAGRAZIA
IMO 9964194
|
15,600 TEU | 2024 |
3.4
|
A |
| 8 |
MSC PALERMO
IMO 9964223
|
15,600 TEU | 2024 |
3.4
|
A |
| 10 |
MSC CARMELA
IMO 9968281
|
16,000 TEU | 2025 |
3.4
|
A |
| 9 |
MSC ANNABELLA
IMO 9963592
|
15,600 TEU | 2025 |
3.4
|
A |
| 11 |
MSC NAPOLI
IMO 9964209
|
15,600 TEU | 2024 |
3.5
|
A |
| 13 |
MSC GERMANY
IMO 9987316
|
16,000 TEU | 2025 |
3.5
|
A |
| 12 |
ONE INNOVATION
IMO 9939137
|
23,000 TEU | 2023 |
3.5
|
A |
| 14 |
MSC MARIE LESLIE
IMO 9968310
|
16,000 TEU | 2025 |
3.5
|
A |
| 15 |
MSC ROME
IMO 9964211
|
15,600 TEU | 2024 |
3.5
|
A |
| 16 |
MSC NERANO
IMO 9963607
|
15,600 TEU | 2025 |
3.5
|
A |
| 17 |
OOCL FINLAND
IMO 9922536
|
24,188 TEU | 2024 |
3.5
|
A |
| 18 |
MSC CATANIA
IMO 9964247
|
15,576 TEU | 2024 |
3.5
|
A |
| 19 |
ONE INTEGRITY
IMO 9933119
|
24,000 TEU | 2023 |
3.5
|
A |
| 20 |
SINGAPORE EXPRESS
IMO 9543093
|
23,660 TEU | 2024 |
3.5
|
A |
| 21 |
ONE INSPIRATION
IMO 9939149
|
23,000 TEU | 2023 |
3.5
|
A |
| 22 |
HANOI EXPRESS
IMO 9540132
|
23,660 TEU | 2023 |
3.5
|
A |
| 23 |
MSC VIOLA
IMO 9947172
|
16,000 TEU | 2024 |
3.6
|
A |
| 24 |
MSC MARTINA MARIA
IMO 9540077
|
15,128 TEU | 2023 |
3.6
|
A |
| 25 |
MSC OLIVIA
IMO 9954761
|
15,500 TEU | 2024 |
3.6
|
A |
| 26 |
MSC DOLETTE
IMO 9968293
|
16,000 TEU | 2025 |
3.6
|
A |
| 27 |
MSC SALERNO
IMO 9968322
|
16,000 TEU | 2025 |
3.6
|
A |
| 28 |
ONE INGENUITY
IMO 9933016
|
24,000 TEU | 2023 |
3.6
|
A |
| 30 |
CMA CGM SEINE
IMO 9987196
|
23,104 TEU | 2025 |
3.6
|
A |
| 29 |
MSC ELEONORE
IMO 9954735
|
15,500 TEU | 2024 |
3.6
|
A |
| 32 |
MSC VERONA
IMO 9987287
|
16,000 TEU | 2024 |
3.7
|
A |
| 31 |
MSC STACEY
IMO 9954759
|
15,500 TEU | 2024 |
3.7
|
A |
| 33 |
MSC AZRA
IMO 9932919
|
15,600 TEU | 2023 |
3.7
|
A |
| 34 |
MSC ARINA
IMO 9839284
|
22,000 TEU | 2019 |
3.7
|
A |
| 36 |
MSC PERLE
IMO 9503732
|
13,092 TEU | 2013 |
3.7
|
A |
| 35 |
ASTRID MAERSK
IMO 9948750
|
14,942 TEU | 2021 |
3.7
|
A |
| 37 |
ANTONIA MAERSK
IMO 9948762
|
16,592 TEU | 2024 |
3.7
|
A |
| 38 |
ALEXANDRA MAERSK
IMO 9948786
|
16,592 TEU | 2024 |
3.7
|
A |
| 39 |
OOCL ABU DHABI
IMO 9922524
|
24,188 TEU | 2024 |
3.7
|
A |
| 40 |
CMA CGM SAINT GERMAIN
IMO 9987201
|
23,876 TEU | 2025 |
3.8
|
A |
| 42 |
CMA CGM RIVOLI
IMO 9839193
|
22,448 TEU | 2021 |
3.8
|
A |
| 41 |
ONE INFINITY
IMO 9933004
|
24,000 TEU | 2023 |
3.8
|
A |
| 43 |
BERLIN MAERSK
IMO 9984560
|
17,148 TEU | 2026 |
3.8
|
A |
| 45 |
MSC JOSEFINA
IMO 9968308
|
16,000 TEU | 2025 |
3.8
|
A |
| 44 |
HMM ALGECIRAS
IMO 9863297
|
23,000 TEU | 2020 |
3.8
|
A |
| 48 |
MSC SIMONA
IMO 9962615
|
202,562 | 2024 |
3.8
|
A |
| 46 |
HMM AMETHYST
IMO 9944467
|
13,248 TEU | 2024 |
3.8
|
A |
| 47 |
MSC TANZANIA
IMO 9978731
|
14,000 TEU | 2025 |
3.8
|
A |
| 50 |
MSC ELISABETTA
IMO 9954747
|
15,500 TEU | 2025 |
3.8
|
A |
| 49 |
MSC OLBIA
IMO 9987299
|
16,000 TEU | 2024 |
3.8
|
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.