While googling this, it seems like there is an international cap on marine fuels for 0.5% sulphur. cruisemapper.com/…/752-cruise-ship-engine-propuls…
A lot of ports and shipping areas require 0.1% sulphur content.
Here’s a thing about MDO and MGO. maritimepage.com/what-are-mgo-and-mdo-fuels-marin…
MGO is 0.1% sulphur content.
MDO is 2% sulphur content.
For comparison, car diesel sulphur content is like 0.001%.
Best source I can find for bunker fuel is 3.5%. So, MDO/MGO are better than bunker fuel, I guess. Feels like a rebrand with minor improvements, so everyone can say “yeh, it’s just diesel. Not bunker fuel”.
But 2% MDO is still a 40% improvement over 3.5% bunker fuel.
Seems like there is a lot of changing and outdated information on this.
And it being related to international trading, laws and standards… There doesn’t seem to be a reliable definitive source on it.
My takeaway is “yeh, it’s not bunker fuel. It’s diesel. But it’s not diesel as we know it from driving cars, trucks, tractors and other plant”