fuel oil has many more times more sulfer that diesel fuel in it.. I helped deliver fuel for a week at a farm co op I worked at diesel fuel the on and the off road type, and fuel oil were not the same stuff… they all came out of different tanks here… .I ran #2 diesel in my boiler for a weekend when I forgot to check my tank until friday night… oops.. hey it looks empty.. a few hours later.. heat stopped… the diesel burned different enough for a slight adjustment of the air intake band…
I think you are both right, for your areas. Diesel is highly variable from area to area and from year to year. It’s a combination of what well the crude oil came from, the refinery that processed it and the changing laws specifying sulphur content and additives. That is one of the reasons we need to tune our burners every year, to account for changes in the makeup of the fuel. The best you can do is ask authoritative people in your area, like suppliers and service personnel, and/or just try it out. If there is any doubt about a fuel, do a tuneup when you make a change.
He is correct about the sulfur per my oil guy. That is going to change even more with the phase in of ULSD. HHO will be exempt initially and diesel will be stepped down in sulphur. That leaves the oil guys in a bind because the same truck will no longer be able to transport diesel and HHO, per the law. It will be interesting to see what happens. My oil guy is under the impression that it will force a lot of small delivery companies out of business because of the expense of extra trucks and tanks.
HHO is allowed to have more sulfur than road diesel but doesn’t always. HHO also has a looser spec. on viscosity, it can be a little thicker or a little thinner than Diesel. Diesel has a specific spec. for cetane which HHO is not even tested for. Diesel “might” have lubrication additives bur often it does not. Often HHO is diesel with a dye added to signify that road taxes have not been paid. Some tank farms only carry “diesel” but add dye when it is sold as HHO. Sometimes you will find that the tank farm will pump summer diesel or off spec diesel into their HHO storage tank. Some times HHO is partially kerosene. It really depends on what is cheaper for the wholesaler that still meets specs.