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 |
|---|---|---|---|---|---|
| 1201 |
STI LEBLON
IMO 9785706
|
49,990 | 2017 |
5.6
|
D |
| 1202 |
ARREBOL
IMO 9939565
|
49,996 | 2024 |
5.6
|
D |
| 1203 |
MINERVA XANTHE
IMO 9318010
|
50,921 | 2003 |
5.6
|
D |
| 1204 |
HAFNIA ZAMBESI
IMO 9393101
|
76,577 | 2010 |
5.6
|
D |
| 1205 |
ENERGY CHANCELLOR
IMO 9292606
|
70,558 | 2005 |
5.6
|
D |
| 1206 |
SOLAR CLAIRE
IMO 9882425
|
49,990 | 2020 |
5.6
|
D |
| 1207 |
SCIROCCO
IMO 9407835
|
73,382 | 2009 |
5.6
|
D |
| 1208 |
HANSA TROMSOE
IMO 9366287
|
51,501 | 2008 |
5.6
|
D |
| 1209 |
STENA IMPERO
IMO 9797400
|
49,683 | 2018 |
5.6
|
D |
| 1210 |
SEA ADVENTURE
IMO 1051226
|
49,888 | 2023 |
5.6
|
D |
| 1211 |
MARLIN AQUAMARINE
IMO 9721906
|
49,999 | 2016 |
5.6
|
D |
| 1212 |
LEFKARA
IMO 9399882
|
49,996 | 2008 |
5.6
|
D |
| 1213 |
ADVANTAGE SUGAR
IMO 9410973
|
156,516 | 2011 |
5.6
|
D |
| 1214 |
CAPETAN ANDREAS
IMO 9284374
|
74,045 | 2007 |
5.6
|
D |
| 1215 |
RADIANT SEA
IMO 9316244
|
73,933 | 2007 |
5.7
|
D |
| 1216 |
FRONTIER MARINER
IMO 9902847
|
50,275 | 2021 |
5.7
|
D |
| 1217 |
SEAWAYS OAK
IMO 9410014
|
51,260 | 2009 |
5.7
|
D |
| 1218 |
OCEAN EUPHROSYNE
IMO 9290658
|
46,920 | 2001 |
5.7
|
D |
| 1219 |
PALERMO
IMO 9414292
|
53,540 | 2010 |
5.7
|
D |
| 1220 |
SOLAR MELISSA
IMO 9882401
|
49,999 | 2020 |
5.7
|
D |
| 1221 |
RIVERSIDE
IMO 9412464
|
115,445 | 2009 |
5.7
|
D |
| 1222 |
STAR MERLIN
IMO 9325609
|
53,755 | 2007 |
5.7
|
D |
| 1223 |
HANSA SEALANCER
IMO 9367695
|
47,451 | 2008 |
5.7
|
D |
| 1224 |
NORD VANGUARD
IMO 9838216
|
49,999 | 2020 |
5.7
|
D |
| 1225 |
ANGEL STAR
IMO 9292345
|
48,635 | 2006 |
5.7
|
D |
| 1226 |
SILVER ETREMA
IMO 9718430
|
49,737 | 2013 |
5.7
|
D |
| 1227 |
MINERVA OCEANIA
IMO 9380075
|
47,402 | 2009 |
5.7
|
D |
| 1228 |
AEGEA
IMO 9326500
|
51,371 | 2003 |
5.7
|
D |
| 1229 |
PEARY SPIRIT
IMO 9466130
|
109,325 | 2011 |
5.7
|
D |
| 1230 |
MINERVA VASO
IMO 9318008
|
50,921 | 2003 |
5.7
|
D |
| 1231 |
SEA SPIKE
IMO 9629952
|
50,034 | 2012 |
5.7
|
D |
| 1232 |
PETREL PACIFIC
IMO 9876397
|
49,853 | 2020 |
5.8
|
D |
| 1233 |
GRAND ACE11
IMO 9443853
|
46,195 | 2008 |
5.8
|
D |
| 1234 |
AL SALAM II
IMO 9328168
|
69,790 | 2007 |
5.8
|
D |
| 1235 |
HELLAS FIGHTER
IMO 9722625
|
49,997 | 2015 |
5.8
|
D |
| 1236 |
YAMILAH-III
IMO 9487263
|
74,866 | 2011 |
5.8
|
D |
| 1237 |
VENDOME STREET
IMO 9573672
|
47,879 | 2011 |
5.8
|
D |
| 1238 |
TP ENDURANCE
IMO 9895197
|
49,999 | 2020 |
5.8
|
D |
| 1239 |
STI WESTMINSTER
IMO 9706437
|
49,687 | 2013 |
5.8
|
D |
| 1240 |
ABDIAS NASCIMENTO
IMO 9453896
|
150,000 | 2017 |
5.8
|
D |
| 1241 |
ELEGANT VOYAGER
IMO 9547506
|
48,006 | 2009 |
5.8
|
D |
| 1242 |
PACIFIC SENTINEL
IMO 9862932
|
50,332 | 2019 |
5.8
|
D |
| 1243 |
VALFOGLIA
IMO 9417309
|
109,060 | 2009 |
5.8
|
D |
| 1244 |
VS PROMISE
IMO 9351438
|
73,669 | 2007 |
5.8
|
D |
| 1245 |
SILVER ENTALINA
IMO 9718428
|
49,737 | 2013 |
5.8
|
D |
| 1246 |
STRIMON
IMO 9798973
|
49,999 | 2015 |
5.8
|
D |
| 1247 |
SILVER HEBA
IMO 9718870
|
49,897 | 2013 |
5.8
|
D |
| 1248 |
MRC LIVA
IMO 9629964
|
49,967 | 2012 |
5.8
|
D |
| 1249 |
JASMINE KNUTSEN
IMO 9273557
|
148,706 | 2005 |
5.8
|
D |
| 1250 |
SCOTT SPIRIT
IMO 9466142
|
109,334 | 2011 |
5.9
|
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.