Most Emission-Efficient Ro-Ro Cargos
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 |
|---|---|---|---|---|---|
| 151 |
BOTNIA SEAWAYS
IMO 9192129
|
8,702 | 2000 |
33.6
|
D |
| 152 |
CITY OF ROTTERDAM
IMO 9473468
|
5,000 | 2011 |
33.7
|
D |
| 153 |
ESTRADEN
IMO 9181077
|
9,741 | 1999 |
33.8
|
D |
| 154 |
FINNWAVE
IMO 9468932
|
14,498 | 2012 |
33.9
|
D |
| 155 |
JUTLANDIA SEA
IMO 9395355
|
11,702 | 2010 |
34.1
|
D |
| 156 |
SUECIA SEAWAYS
IMO 9153020
|
11,089 | 1999 |
34.7
|
D |
| 157 |
GALLIPOLI SEAWAYS
IMO 9215476
|
9,865 | 2001 |
34.7
|
D |
| 158 |
LONGSTONE
IMO 9848479
|
11,900 | 2019 |
34.8
|
D |
| 159 |
FIONIA SEA
IMO 9395343
|
11,702 | 2006 |
34.8
|
D |
| 160 |
ELISABETH RUSS
IMO 9186429
|
7,296 | 1999 |
34.9
|
D |
| 161 |
CORONA SEA
IMO 9357597
|
11,702 | 2006 |
35.0
|
D |
| 162 |
HANNAH KRISTINA
IMO 9159933
|
4,804 | 1999 |
35.0
|
D |
| 163 |
PATRIS
IMO 9242388
|
9,865 | 2002 |
35.2
|
D |
| 164 |
EUROCARGO BARI
IMO 9471082
|
10,780 | 2012 |
35.3
|
D |
| 165 |
EUROCARGO VALENCIA
IMO 9468918
|
14,467 | 2012 |
35.4
|
D |
| 166 |
HAFNIA SEA
IMO 9357602
|
11,702 | 2008 |
35.5
|
D |
| 167 |
WILHELMINE
IMO 9539080
|
6,374 | 2012 |
35.5
|
D |
| 168 |
ABU SAMRAH
IMO 9925655
|
12,089 | 2023 |
35.6
|
D |
| 169 |
LISTA
IMO 9503627
|
11,415 | 2011 |
36.0
|
D |
| 170 |
EUROCARGO LIVORNO
IMO 9471070
|
10,780 | 2012 |
36.1
|
D |
| 171 |
EUROCARGO VENEZIA
IMO 9465552
|
10,765 | 2011 |
36.8
|
D |
| 172 |
MN PELICAN
IMO 9170999
|
8,491 | 1999 |
36.8
|
D |
| 173 |
EUROCARGO CAGLIARI
IMO 9471068
|
10,780 | 2012 |
37.2
|
D |
| 174 |
OLYMPOS SEAWAYS
IMO 9242390
|
9,865 | 2002 |
37.5
|
D |
| 175 |
PETUNIA SEAWAYS
IMO 9259501
|
10,407 | 2004 |
38.1
|
D |
| 176 |
LISMORE
IMO 9848467
|
11,949 | 2018 |
38.2
|
D |
| 177 |
EUROCARGO GENOVA
IMO 9458951
|
10,780 | 2010 |
38.3
|
E |
| 178 |
FINNPULP
IMO 9212644
|
11,787 | 2002 |
38.5
|
E |
| 179 |
GLYVURSNES
IMO 9198977
|
7,226 | 1999 |
38.6
|
E |
| 180 |
STENA FORETELLER
IMO 9214666
|
10,539 | 2001 |
39.4
|
E |
| 181 |
FINNMILL
IMO 9212656
|
11,849 | 2002 |
39.5
|
E |
| 182 |
EUROCARGO ROMA
IMO 9465526
|
10,786 | 2010 |
39.7
|
E |
| 183 |
EUROCARGO RAVENNA
IMO 9471056
|
10,779 | 2012 |
40.3
|
E |
| 184 |
MN TOUCAN
IMO 9112466
|
4,329 | 1995 |
40.4
|
E |
| 185 |
CAROLINE RUSS
IMO 9197533
|
7,296 | 1999 |
40.6
|
E |
| 186 |
SARDINIA
IMO 9138800
|
12,350 | 2004 |
40.7
|
E |
| 187 |
EUROCARGO MALTA
IMO 9465514
|
10,787 | 2010 |
41.2
|
E |
| 188 |
BRENAS CARGO
IMO 9160774
|
7,382 | 1998 |
42.1
|
E |
| 189 |
MN COLIBRI
IMO 9207390
|
4,169 | 2000 |
42.1
|
E |
| 190 |
EUROCARGO PALERMO
IMO 9465538
|
10,770 | 2010 |
42.4
|
E |
| 191 |
EUROCARGO ALEXANDRIA
IMO 9465540
|
10,773 | 2011 |
42.5
|
E |
| 192 |
BAHIA CARGO
IMO 9207895
|
9,109 | 2001 |
44.7
|
E |
| 193 |
BENTAYGA CARGO
IMO 9207883
|
9,096 | 2000 |
45.0
|
E |
| 194 |
NEPTUNE OKEANIS
IMO 9306706
|
6,200 | 2005 |
45.4
|
E |
| 195 |
BRITANNIA SEAWAYS
IMO 9153032
|
11,089 | 2000 |
46.0
|
E |
| 196 |
NEPTUNE THELISIS
IMO 9306718
|
6,200 | 2006 |
46.3
|
E |
| 197 |
AUTOSUN
IMO 9227053
|
6,670 | 2000 |
46.3
|
E |
| 198 |
MAYAR
IMO 9226360
|
8,800 | 2001 |
46.8
|
E |
| 199 |
AUTOSTAR
IMO 9206786
|
6,670 | 2000 |
47.1
|
E |
| 200 |
FJARDVAGEN
IMO 7226952
|
2,566 | 1972 |
48.8
|
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.