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 |
|---|---|---|---|---|---|
| 48 |
EAGLE VICTORIA
IMO 9739513
|
299,392 | 2016 |
1.9
|
A |
| 51 |
NEW COROLLA
IMO 9900679
|
307,552 | 2021 |
1.9
|
A |
| 54 |
NISSOS DESPOTIKO
IMO 9845697
|
318,744 | 2019 |
1.9
|
A |
| 53 |
NEW AMBITION
IMO 9900667
|
307,620 | 2021 |
1.9
|
A |
| 55 |
MARAN ATALANTA
IMO 9810393
|
319,398 | 2018 |
1.9
|
A |
| 56 |
NEW RENOWN
IMO 9759604
|
318,689 | 2017 |
1.9
|
A |
| 57 |
GEM NO. 1
IMO 9735361
|
302,652 | 2016 |
1.9
|
A |
| 58 |
FRONT MORGAN
IMO 9877781
|
299,999 | 2021 |
1.9
|
A |
| 61 |
EAGLE VALENCE
IMO 9910234
|
299,244 | 2022 |
1.9
|
A |
| 60 |
KHK EMPRESS
IMO 9830965
|
314,014 | 2019 |
1.9
|
A |
| 59 |
DEGAS
IMO 9926673
|
299,829 | 2022 |
1.9
|
A |
| 62 |
DIAS I
IMO 9858474
|
299,999 | 2020 |
1.9
|
A |
| 63 |
FRONT BEAVER
IMO 9943748
|
300,008 | 2023 |
2.0
|
A |
| 64 |
MARAN LEO
IMO 9602473
|
319,450 | 2010 |
2.0
|
A |
| 65 |
MARAN ARTEMIS
IMO 9753002
|
319,398 | 2016 |
2.0
|
A |
| 66 |
ZOURVA
IMO 9679593
|
319,000 | 2010 |
2.0
|
A |
| 68 |
SPHERICAL
IMO 9890977
|
313,166 | 2018 |
2.0
|
A |
| 67 |
NISSOS KEA
IMO 9920758
|
300,323 | 2022 |
2.0
|
A |
| 69 |
NEW VOYAGE
IMO 9686364
|
313,733 | 2015 |
2.0
|
A |
| 70 |
FPMC C NOBLE
IMO 9419955
|
297,258 | 2012 |
2.0
|
A |
| 72 |
SHADEN
IMO 9779848
|
298,750 | 2017 |
2.0
|
A |
| 71 |
SOPHIA
IMO 9776559
|
319,398 | 2017 |
2.0
|
A |
| 73 |
FRONT GAULA
IMO 9933652
|
299,982 | 2022 |
2.0
|
A |
| 74 |
MARAN ARES
IMO 9796872
|
319,398 | 2017 |
2.0
|
A |
| 75 |
ALMI HYDRA
IMO 9583720
|
319,357 | 2013 |
2.0
|
A |
| 76 |
CARIBBEAN GLORY
IMO 9788875
|
301,528 | 2017 |
2.0
|
A |
| 77 |
NISSOS NIKOURIA
IMO 9920760
|
300,323 | 2022 |
2.0
|
A |
| 81 |
AROSA
IMO 9784386
|
299,323 | 2017 |
2.0
|
A |
| 80 |
NEW DREAM
IMO 9689976
|
318,292 | 2014 |
2.0
|
A |
| 79 |
FRONT VEFSNA
IMO 9730098
|
297,638 | 2017 |
2.0
|
A |
| 78 |
RED NOVA
IMO 9602643
|
319,778 | 2013 |
2.0
|
A |
| 82 |
SEA MAJESTY
IMO 9783344
|
308,206 | 2017 |
2.1
|
A |
| 83 |
NISSOS DONOUSSA
IMO 9853840
|
318,744 | 2019 |
2.1
|
A |
| 84 |
AQUILA
IMO 9521473
|
319,329 | 2008 |
2.1
|
A |
| 85 |
FARHAH
IMO 9484742
|
319,329 | 2010 |
2.1
|
A |
| 86 |
GULF LOYALTY
IMO 9441245
|
316,373 | 2011 |
2.1
|
A |
| 87 |
NEW MERIT
IMO 9706396
|
318,348 | 2017 |
2.1
|
A |
| 88 |
SIREN
IMO 9405423
|
158,583 | 2009 |
2.1
|
A |
| 89 |
COSWISH LAKE
IMO 9804277
|
318,737 | 2018 |
2.1
|
A |
| 90 |
ARAGONA
IMO 9513115
|
319,319 | 2012 |
2.1
|
A |
| 92 |
HELIOS
IMO 9941673
|
302,093 | 2017 |
2.1
|
A |
| 91 |
MARAN ARETE
IMO 9776547
|
319,398 | 2015 |
2.1
|
A |
| 94 |
VL PIONEER
IMO 9683661
|
319,300 | 2014 |
2.1
|
A |
| 93 |
SAN JACINTO
IMO 9730373
|
158,734 | 2014 |
2.1
|
A |
| 95 |
BREST
IMO 9941867
|
157,071 | 2023 |
2.2
|
A |
| 96 |
EAGLE VENICE
IMO 9728710
|
298,991 | 2016 |
2.2
|
A |
| 98 |
HORTEN
IMO 9740342
|
297,670 | 2018 |
2.2
|
A |
| 97 |
SUR
IMO 9870824
|
299,997 | 2020 |
2.2
|
A |
| 100 |
MARAN ATHENA
IMO 9770505
|
319,398 | 2016 |
2.2
|
A |
| 99 |
NAVE ALLEGRO
IMO 9876414
|
313,433 | 2020 |
2.2
|
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 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.