Sulfur in diesel fuel

[AJH]

Have just purchased a1989 Californian motor yacht. The previous owner only used the saddle tanks when traveling. When purchased the main tank had approximately 200 gallon s of fuel and not sure how old. The engines are Detroit Diesel 671T. I've had the fuel tested and results show the sulfur content is 950ppm. Does anyone know if it would be detrimental to the engines to use the fuel with this amount of sulfur?
Thanks in advance.

 

[Mambo42]

I guess you still have the old injectors and the only thing sulfur will do is clog them up a bit if you run the engine at low rpm. As a result the engine will smoke black, but that is about it. Once you burn that fuel you can put in a limited amount of diesel, add some injector cleaner and burn the sulfur build up away. If the injectors are really dirty, just take them out, clean them and you will be fine again.

On the island of Curacao we were driving on high sulfur diesel well into the 2000s, all the diesel engines were smoking like a chimney. Only the common rail diesels were unable to run on high sulfur diesel.

 

[DavidM]

950 ppm of sulfur in diesel was normal before EPA regulations forced refineries to remove it (by hydro treating) to get it down to 15 ppm. Since your engine was built to deal with the high sulfur, it shouldn’t be a problem.

But that also means that the diesel in that tank is very old if it has 950 ppm sulfur. It is at least 18 years old because 2006 was when the low sulfur requirement went into effect.

So I would get that tank polished to remove any other crap that may be in the fuel before using, but don’t worry about the sulfur.

David

 

[rslifkin]

950 ppm of sulfur in diesel was normal before EPA regulations forced refineries to remove it (by hydro treating) to get it down to 15 ppm. Since your engine was built to deal with the high sulfur, it shouldn’t be a problem.

But that also means that the diesel in that tank is very old if it has 950 ppm sulfur. It is at least 18 years old because 2006 was when the low sulfur requirement went into effect.

So I would get that tank polished to remove any other crap that may be in the fuel before using, but don’t worry about the sulfur.

David

IIRC off-road diesel was allowed 500 ppm for a few years after the on-road requirement dropped to 15 ppm. But it's still definitely old fuel.