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 |
|---|---|---|---|---|---|
| 201 |
THERMOPYLAE
IMO 9702443
|
23,786 | 2015 |
15.1
|
C |
| 202 |
BRANDS HATCH
IMO 9999967
|
19,160 | 2025 |
15.1
|
C |
| 203 |
CMA CGM MONACO
IMO 9946075
|
19,086 | 2024 |
15.1
|
C |
| 204 |
GLOVIS SPLENDOR
IMO 9702431
|
20,056 | 2014 |
15.1
|
C |
| 205 |
MIRACULOUS ACE
IMO 9293521
|
19,381 | 2006 |
15.1
|
C |
| 206 |
OCEANUS LEADER
IMO 9553488
|
21,351 | 2013 |
15.1
|
C |
| 207 |
MORNING CAPO
IMO 9663295
|
20,139 | 2013 |
15.2
|
C |
| 208 |
GRAND MARK
IMO 9228306
|
20,670 | 2000 |
15.2
|
C |
| 209 |
CRYSTAL RAY
IMO 9210440
|
21,400 | 2000 |
15.2
|
C |
| 210 |
JIUYANG BONANZA
IMO 9330616
|
19,635 | 2006 |
15.2
|
C |
| 211 |
CAPE TOWN HIGHWAY
IMO 9565558
|
21,676 | 2011 |
15.2
|
C |
| 212 |
OLYMPIAN HIGHWAY
IMO 9757993
|
20,445 | 2017 |
15.3
|
C |
| 213 |
AQUARIUS ACE
IMO 9150339
|
14,353 | 1998 |
15.3
|
C |
| 214 |
EUPHONY ACE
IMO 9293595
|
18,944 | 2005 |
15.3
|
C |
| 215 |
MORNING CONCERT
IMO 9312822
|
21,279 | 2006 |
15.3
|
C |
| 216 |
HAI HE KOU
IMO 9991769
|
19,112 | 2025 |
15.3
|
C |
| 217 |
DIGNITY LEADER
IMO 9441506
|
20,589 | 2010 |
15.4
|
C |
| 218 |
SEA PATRIS
IMO 8415794
|
13,895 | 1985 |
15.4
|
C |
| 219 |
VOLANS LEADER
IMO 9381237
|
20,168 | 2007 |
15.4
|
C |
| 220 |
ASIAN DYNASTY
IMO 9203588
|
21,224 | 1999 |
15.4
|
C |
| 221 |
SIEM CICERO
IMO 9762534
|
17,416 | 2017 |
15.4
|
C |
| 222 |
AUTO ADVANCE
IMO 9881299
|
12,457 | 2021 |
15.4
|
C |
| 223 |
XIANG JIANG KOU
IMO 9985394
|
19,358 | 2025 |
15.4
|
C |
| 224 |
HOEGH JEDDAH
IMO 9673381
|
20,407 | 2014 |
15.4
|
C |
| 225 |
AMETHYST ACE
IMO 9397999
|
18,760 | 2008 |
15.4
|
C |
| 226 |
UNITED SPIRIT
IMO 9185047
|
14,067 | 2000 |
15.4
|
C |
| 227 |
TAIPAN
IMO 9311866
|
21,021 | 2006 |
15.5
|
C |
| 228 |
CRUX LEADER
IMO 9177428
|
21,523 | 1998 |
15.5
|
C |
| 229 |
GLOVIS SYMPHONY
IMO 9702429
|
19,911 | 2014 |
15.5
|
C |
| 230 |
SEBRING
IMO 9434321
|
15,154 | 2009 |
15.5
|
C |
| 231 |
MORNING CATHERINE
IMO 9338711
|
22,447 | 2008 |
15.5
|
C |
| 232 |
HOEGH MANILA
IMO 9368912
|
17,252 | 2007 |
15.5
|
C |
| 233 |
MORNING LENA
IMO 9446001
|
27,295 | 2010 |
15.6
|
C |
| 234 |
HAWAIIAN HIGHWAY
IMO 9712632
|
20,606 | 2015 |
15.6
|
C |
| 235 |
OCEAN BREEZE
IMO 9987794
|
19,209 | 2026 |
15.6
|
C |
| 236 |
AICC HUANGHU
IMO 1018377
|
18,773 | 2025 |
15.6
|
C |
| 237 |
HUANG HE KOU
IMO 9985368
|
19,301 | 2024 |
15.6
|
C |
| 238 |
RCC ASIA
IMO 9391581
|
21,037 | 2009 |
15.7
|
C |
| 239 |
MORNING LADY
IMO 9445980
|
27,343 | 2010 |
15.7
|
C |
| 240 |
BROOKLANDS
IMO 9748289
|
18,332 | 2017 |
15.7
|
C |
| 241 |
THALATTA
IMO 9702455
|
23,786 | 2015 |
15.8
|
C |
| 242 |
DIONYSOS LEADER
IMO 9426350
|
21,438 | 2009 |
15.8
|
C |
| 243 |
ORION HIGHWAY
IMO 9728071
|
20,532 | 2016 |
15.8
|
C |
| 244 |
RCC AFRICA
IMO 9277814
|
21,214 | 2004 |
15.8
|
C |
| 245 |
OPAL ACE
IMO 9539183
|
18,507 | 2011 |
15.8
|
C |
| 246 |
GLOVIS SELENE
IMO 9964170
|
19,322 | 2025 |
15.8
|
C |
| 247 |
SAIC ANJI ETERNITY
IMO 9955040
|
19,116 | 2024 |
15.9
|
C |
| 248 |
GRAND EAGLE
IMO 9267663
|
19,048 | 2003 |
15.9
|
C |
| 249 |
CRONUS LEADER
IMO 9464455
|
20,096 | 2008 |
15.9
|
C |
| 250 |
HOEGH YOKOHAMA
IMO 9185451
|
16,919 | 2000 |
15.9
|
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.