Most Emission-Efficient Vehicle 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 |
|---|---|---|---|---|---|
| 401 |
SEVEN SEAS HIGHWAY
IMO 9238521
|
17,232 | 2001 |
19.1
|
E |
| 402 |
VIKING ADVENTURE
IMO 9673018
|
18,375 | 2015 |
19.1
|
E |
| 403 |
MARGUERITE ACE
IMO 9426386
|
17,237 | 2009 |
19.2
|
E |
| 404 |
GLOVIS STELLA
IMO 9749570
|
19,638 | 2016 |
19.2
|
E |
| 405 |
PRIMROSE ACE
IMO 9355185
|
17,339 | 2007 |
19.4
|
E |
| 406 |
VIKING SYDNEY
IMO 9368900
|
17,311 | 2007 |
19.4
|
E |
| 407 |
VIKING QUEEN
IMO 9318462
|
16,890 | 2007 |
19.4
|
E |
| 408 |
LEO SPIRIT
IMO 9620695
|
16,758 | 2012 |
19.5
|
E |
| 409 |
GLOVIS SILVER
IMO 9775828
|
20,884 | 2017 |
19.5
|
E |
| 410 |
GALAXY ACE
IMO 9624237
|
18,878 | 2012 |
19.5
|
E |
| 411 |
VIKING BRASILIA
IMO 9368895
|
17,252 | 2007 |
19.8
|
E |
| 412 |
PLEIADES SPIRIT
IMO 9409326
|
17,424 | 2008 |
19.8
|
E |
| 413 |
GRANDE ROMA
IMO 9247936
|
14,567 | 2003 |
19.9
|
E |
| 414 |
LAVENDER ACE
IMO 9363948
|
17,262 | 2008 |
19.9
|
E |
| 415 |
GRANDE MIRAFIORI
IMO 9782687
|
15,853 | 2019 |
20.0
|
E |
| 416 |
GRANDE NEW YORK
IMO 9784049
|
18,360 | 2017 |
20.0
|
E |
| 417 |
DREAM DIVA
IMO 9325790
|
15,068 | 2007 |
20.1
|
E |
| 418 |
MICHIGAN HIGHWAY
IMO 9339832
|
17,673 | 2008 |
20.1
|
E |
| 419 |
GRANDE HALIFAX
IMO 9784051
|
18,353 | 2018 |
20.2
|
E |
| 420 |
VIKING MEDITERRANEAN
IMO 9451006
|
12,283 | 2010 |
20.3
|
E |
| 421 |
GAN JIANG KOU
IMO 9985382
|
19,369 | 2025 |
20.5
|
E |
| 422 |
ORCHID ACE
IMO 9381677
|
17,289 | 2008 |
20.5
|
E |
| 423 |
NEPTUNE KALLOS
IMO 9442122
|
11,215 | 2010 |
20.6
|
E |
| 424 |
GRAND NEPTUNE
IMO 9303209
|
18,318 | 2006 |
20.6
|
E |
| 425 |
TARIFA
IMO 9327748
|
21,120 | 2007 |
20.7
|
E |
| 426 |
NEPTUNE PHOS
IMO 9451719
|
11,174 | 2009 |
21.0
|
E |
| 427 |
GRAND AURORA
IMO 9279331
|
18,381 | 2004 |
21.1
|
E |
| 428 |
CATTLEYA ACE
IMO 9544918
|
16,384 | 2011 |
21.1
|
E |
| 429 |
COSCO SHENGSHI
IMO 9454711
|
14,868 | 2011 |
21.3
|
E |
| 430 |
NEPTUNE ODYSSEY
IMO 9440095
|
11,418 | 2010 |
21.3
|
E |
| 431 |
NEPTUNE ITHAKI
IMO 9440083
|
11,010 | 2010 |
21.3
|
E |
| 432 |
NEPTUNE KEFALONIA
IMO 9438717
|
11,010 | 2009 |
21.4
|
E |
| 433 |
GRANDE HOUSTON
IMO 9782699
|
15,853 | 2020 |
21.5
|
E |
| 434 |
GRANDE TORINO
IMO 9782675
|
15,853 | 2018 |
21.5
|
E |
| 435 |
SILVER SUN
IMO 8519710
|
9,772 | 1988 |
21.6
|
E |
| 436 |
GRANDE TEXAS
IMO 9796365
|
15,853 | 2021 |
21.6
|
E |
| 437 |
NEPTUNE HORIZON
IMO 9451721
|
11,215 | 2010 |
21.7
|
E |
| 438 |
SILVER SOUL
IMO 9153783
|
13,695 | 1997 |
21.8
|
E |
| 439 |
PIRANHA
IMO 9088249
|
12,490 | 1997 |
21.9
|
E |
| 440 |
NEPTUNE ILIAD
IMO 9440100
|
11,409 | 2010 |
22.0
|
E |
| 441 |
GLOVIS CARDINAL
IMO 9419759
|
22,342 | 2012 |
22.0
|
E |
| 442 |
GRANDE ITALIA
IMO 9227912
|
12,594 | 2001 |
22.3
|
E |
| 443 |
NEPTUNE THARROS
IMO 9431850
|
12,250 | 2011 |
22.5
|
E |
| 444 |
GRANDE SPAGNA
IMO 9227924
|
12,590 | 2002 |
22.8
|
E |
| 445 |
NEPTUNE ETHOS
IMO 9431862
|
12,250 | 2011 |
22.8
|
E |
| 446 |
PARANA
IMO 9427964
|
12,868 | 2012 |
22.9
|
E |
| 447 |
GRANDE NAPOLI
IMO 9247924
|
14,565 | 2003 |
23.0
|
E |
| 448 |
GRANDE CALIFORNIA
IMO 9796377
|
15,853 | 2021 |
23.0
|
E |
| 449 |
MONZA
IMO 9358888
|
12,303 | 2008 |
23.1
|
E |
| 450 |
GRANDE SICILIA
IMO 9312092
|
12,420 | 2006 |
23.1
|
E |
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.