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 2024. 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 |
|---|---|---|---|---|---|
| 152 |
COSTAS P
IMO 9934321
|
157,010 | 2023 |
2.3
|
A |
| 154 |
BLUE NOVA
IMO 9534846
|
298,000 | 2011 |
2.3
|
A |
| 151 |
FRONT CORAL
IMO 9743203
|
157,522 | 2017 |
2.3
|
A |
| 153 |
ADVANTAGE VERITY
IMO 9762998
|
299,998 | 2014 |
2.3
|
A |
| 155 |
CAP LARA
IMO 9330874
|
158,826 | 2007 |
2.3
|
A |
| 157 |
MARAN ANTARES
IMO 9581203
|
317,052 | 2012 |
2.3
|
A |
| 156 |
GULF LOYALTY
IMO 9441245
|
316,373 | 2011 |
2.3
|
A |
| 158 |
AQUAHONOR
IMO 9925136
|
157,746 | 2022 |
2.3
|
A |
| 159 |
RHYTHMIC
IMO 9819856
|
159,196 | 2019 |
2.3
|
A |
| 160 |
BASRA
IMO 9876438
|
312,965 | 2018 |
2.3
|
A |
| 161 |
MARAN THALEIA
IMO 9527295
|
321,225 | 2011 |
2.3
|
A |
| 162 |
ATLANTIC
IMO 9912139
|
158,337 | 2022 |
2.4
|
A |
| 164 |
HOMERIC
IMO 9819844
|
157,000 | 2019 |
2.4
|
A |
| 163 |
HABRUT
IMO 9500730
|
319,439 | 2012 |
2.4
|
A |
| 165 |
C. SPIRIT
IMO 9643269
|
313,998 | 2013 |
2.4
|
A |
| 167 |
MARAN ARIES
IMO 9295000
|
320,870 | 2006 |
2.4
|
A |
| 166 |
SONANGOL MAIOMBE
IMO 9766322
|
156,935 | 2017 |
2.4
|
A |
| 169 |
MARAN THETIS
IMO 9421427
|
320,105 | 2012 |
2.4
|
A |
| 168 |
CARIBBEAN GLORY
IMO 9788875
|
301,528 | 2017 |
2.4
|
A |
| 174 |
MARAN LYRA
IMO 9559406
|
317,924 | 2010 |
2.4
|
A |
| 173 |
CASCADE SPIRIT
IMO 9399492
|
156,852 | 2009 |
2.4
|
A |
| 172 |
NORDIC TELLUS
IMO 9818230
|
157,407 | 2018 |
2.4
|
A |
| 171 |
SEA CORAL
IMO 9920708
|
157,104 | 2020 |
2.4
|
A |
| 170 |
OCEANIS
IMO 9532757
|
320,780 | 2011 |
2.4
|
A |
| 177 |
NORDIC AQUARIUS
IMO 9818216
|
157,338 | 2018 |
2.4
|
A |
| 176 |
ANTARCTICA
IMO 9910492
|
163,128 | 2022 |
2.4
|
A |
| 178 |
PATRIOTIC
IMO 9819832
|
159,090 | 2019 |
2.4
|
A |
| 175 |
NEW SUCCESS
IMO 9434632
|
296,713 | 2010 |
2.4
|
A |
| 180 |
MINERVA EVROPI
IMO 9785237
|
159,000 | 2015 |
2.4
|
A |
| 179 |
POLIEGOS
IMO 9746621
|
157,540 | 2017 |
2.4
|
A |
| 181 |
GREAT LADY
IMO 9286138
|
308,930 | 2005 |
2.4
|
A |
| 182 |
KIMOLOS
IMO 9791145
|
159,159 | 2018 |
2.4
|
A |
| 183 |
MARAN ASPASIA
IMO 9879997
|
157,946 | 2019 |
2.4
|
A |
| 184 |
FRONT CLIPPER
IMO 9759771
|
157,351 | 2017 |
2.4
|
A |
| 186 |
DELTA SUPREME
IMO 9585895
|
159,031 | 2012 |
2.4
|
A |
| 185 |
STARWAY
IMO 9900801
|
157,551 | 2022 |
2.4
|
A |
| 188 |
FRONT CLASSIC
IMO 9759769
|
157,434 | 2017 |
2.4
|
A |
| 187 |
ATLANTIC M
IMO 9907237
|
156,668 | 2022 |
2.4
|
A |
| 189 |
LORD BYRON 21
IMO 9889954
|
156,921 | 2021 |
2.4
|
A |
| 190 |
POPI P
IMO 9934319
|
157,010 | 2023 |
2.4
|
A |
| 193 |
NORDIC CYGNUS
IMO 9818228
|
157,526 | 2018 |
2.4
|
A |
| 192 |
RELIABLE WARRIOR
IMO 9753557
|
159,058 | 2014 |
2.4
|
A |
| 191 |
YASA SOUTHERN CROSS
IMO 9534030
|
318,438 | 2006 |
2.4
|
A |
| 194 |
UNIVERSAL FRONTIER
IMO 9829382
|
299,546 | 2019 |
2.5
|
A |
| 196 |
AEGEAN MARATHON
IMO 9745225
|
158,913 | 2016 |
2.5
|
A |
| 195 |
MARIA
IMO 9530890
|
157,523 | 2012 |
2.5
|
A |
| 199 |
ZEUS
IMO 9886378
|
159,153 | 2021 |
2.5
|
A |
| 198 |
MARLIN SARDINIA
IMO 9835862
|
156,606 | 2019 |
2.5
|
A |
| 197 |
BARAKAH
IMO 9902615
|
307,925 | 2021 |
2.5
|
A |
| 200 |
MARFA
IMO 9773478
|
159,512 | 2017 |
2.5
|
A |
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 2024 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.