Most Emission-Efficient Oil Tankers
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 |
|---|---|---|---|---|---|
| 1151 |
ENERGY AFRODITE
IMO 9942304
|
49,812 | 2022 |
5.3
|
D |
| 1152 |
RAINBOW SPIRIT
IMO 9837171
|
129,734 | 2020 |
5.3
|
D |
| 1153 |
MINERVA LIBRA
IMO 9317951
|
116,779 | 2007 |
5.3
|
D |
| 1154 |
FLAGSHIP TULIP
IMO 9594896
|
74,986 | 2013 |
5.3
|
D |
| 1155 |
LIA
IMO 9417751
|
73,723 | 2008 |
5.3
|
D |
| 1156 |
MARAN CURRENT
IMO 9843924
|
129,801 | 2020 |
5.3
|
D |
| 1157 |
KLARA
IMO 9405904
|
51,755 | 2010 |
5.3
|
D |
| 1158 |
PRESIDENT I
IMO 9312444
|
64,999 | 2007 |
5.3
|
D |
| 1159 |
SAFEEN ELONA
IMO 9488011
|
105,258 | 2012 |
5.3
|
D |
| 1160 |
PACIFIC MOONSTONE
IMO 9892078
|
50,192 | 2021 |
5.3
|
D |
| 1161 |
SILVER ZOE
IMO 9692325
|
49,635 | 2015 |
5.3
|
D |
| 1162 |
MAISTROS
IMO 9407847
|
73,334 | 2006 |
5.3
|
D |
| 1163 |
MARAN TIDE
IMO 9843912
|
129,632 | 2020 |
5.3
|
D |
| 1164 |
BANDA
IMO 9337406
|
105,576 | 2007 |
5.3
|
D |
| 1165 |
SILVER LINDA
IMO 9683415
|
49,746 | 2015 |
5.3
|
D |
| 1166 |
HEATHER KNUTSEN
IMO 9273064
|
148,644 | 2005 |
5.3
|
D |
| 1167 |
HISTRIA NARVI
IMO 9800829
|
40,000 | 2024 |
5.4
|
D |
| 1168 |
HELLAS AVATAR
IMO 9722613
|
49,997 | 2015 |
5.4
|
D |
| 1169 |
HAFNIA LIONESS
IMO 9675509
|
49,999 | 2014 |
5.4
|
D |
| 1170 |
LVM WARRIOR
IMO 9694189
|
49,997 | 2015 |
5.4
|
D |
| 1171 |
FLAGSHIP SAGE
IMO 9471329
|
74,158 | 2011 |
5.4
|
D |
| 1172 |
STI QUEENS
IMO 9707273
|
49,990 | 2015 |
5.4
|
D |
| 1173 |
OCEAN NISA
IMO 9553749
|
49,999 | 2022 |
5.4
|
D |
| 1174 |
NEAPOLIS
IMO 9792199
|
73,937 | 2018 |
5.4
|
D |
| 1175 |
ALFIOS
IMO 9884241
|
49,999 | 2020 |
5.4
|
D |
| 1176 |
JOROPO
IMO 9380087
|
47,410 | 2009 |
5.4
|
D |
| 1177 |
BLUE SEA
IMO 9413028
|
105,416 | 2006 |
5.4
|
D |
| 1178 |
JAG PRACHI
IMO 9590723
|
51,486 | 2013 |
5.5
|
D |
| 1179 |
SEAMUSIC
IMO 9407445
|
112,922 | 2009 |
5.5
|
D |
| 1180 |
STI REGINA
IMO 9686728
|
49,990 | 2014 |
5.5
|
D |
| 1181 |
SOVEREIGN
IMO 9390939
|
74,998 | 2009 |
5.5
|
D |
| 1182 |
OLYMPIC FLAG
IMO 9271341
|
155,009 | 2004 |
5.5
|
D |
| 1183 |
ENERGY APOLLO
IMO 9891438
|
49,812 | 2020 |
5.5
|
D |
| 1184 |
PARTRIDGE PACIFIC
IMO 9960291
|
49,808 | 2023 |
5.5
|
D |
| 1185 |
HISTRIA ATLAS
IMO 9800790
|
40,000 | 2019 |
5.5
|
D |
| 1186 |
SILVER VALERIE
IMO 9682320
|
49,715 | 2014 |
5.5
|
D |
| 1187 |
OKEE JOHN T
IMO 9311036
|
53,712 | 2006 |
5.5
|
D |
| 1188 |
SILVER HANNAH
IMO 9682409
|
49,680 | 2014 |
5.5
|
D |
| 1189 |
KRITI JOURNEY
IMO 9440538
|
112,723 | 2010 |
5.5
|
D |
| 1190 |
KRITI SAMARIA
IMO 9329409
|
105,865 | 2007 |
5.5
|
D |
| 1191 |
STI MAGNETIC
IMO 9829485
|
47,499 | 2019 |
5.5
|
D |
| 1192 |
LARVIK
IMO 9307346
|
61,213 | 2006 |
5.5
|
D |
| 1193 |
DAS
IMO 9439802
|
50,261 | 2009 |
5.5
|
D |
| 1194 |
BURGAN
IMO 9656022
|
46,330 | 2014 |
5.5
|
D |
| 1195 |
SOLAR KATHERINE
IMO 9882396
|
49,990 | 2020 |
5.5
|
D |
| 1196 |
YUME
IMO 9459230
|
45,994 | 2010 |
5.5
|
D |
| 1197 |
NAVE JUPITER
IMO 9657038
|
50,240 | 2011 |
5.5
|
D |
| 1198 |
IPANEMA STREET
IMO 9402770
|
47,378 | 2006 |
5.5
|
D |
| 1199 |
TUVA KNUTSEN
IMO 9887968
|
152,744 | 2021 |
5.6
|
D |
| 1200 |
STI GALATA
IMO 9785689
|
51,546 | 2017 |
5.6
|
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.