Furnace oil...
 

93 7.3 non turbo, I've been running furnace oil in the back tank, diesel in the front for a while now and it runs great. Question is, (and I've had many answers) what is the difference? I've heard road tax is the only difference, other say more parrafin in furnace oil, others say it'll blow the motor.
Curious what every one thinks

A big difference is sulfur. Furnace oil has 0.2% sulfur. Old diesel had .05%sulfur. 2007+ diesel has .0015% sulfur.

On a truck as old as yours, sulfur won't make too much difference, but on late model trucks with diesel catalysts, it will clog the catalysts.

Don't get caught!

Thanks for the reply, I'm not concerned about getting caught. Farm country and NOBODY has even been considered getting caught! haha. 67cents a litre instead of $1.17 is about $38.00 saved per fill up!
I'm just curious if anybody knows for sure the difference in make up or is it the same except road tax. Sulphur content is interesting, considering sulphur is what lubricates the IP, and everybody yelled when they started taking it out because of increased wear. I fire up on diesel, get on the highway to work and switch to oil, then switch back 5km's from work. (45 min drive each way) It's good practise for when I convert to WVO eh? Lol!

Again, thanks for the reply's.

That's pretty interesting!

Actually, it's not the sulphur that lubricates. I admit that I thought that but I found out otherwise.

However, when the process is done that removes the sulphur, it removes the compounds that do lubricate.

You can actually ad two stroke oil or some vegetable oil to get lubrication into the fuel with better results than using a commercial chemical that's more expensive.

Sulfur is an abrasive agent. It's the main difference between metal cutting oil and lubricating oil.
Sulfur won't 'clog' a catalytic converter any more than leaded gasoline would. The compounds coat the catalyst and render the beads incapable of converting, so the emissions go way up, but there is no change in air flow.
Your 93 wouldn't have a catalyst, so the non-existent conversion efficiency isn't changed.
But be wary, Is the heating oil blended to flow when it's in someone's 10C basement in a 1000 liter tank, or is it suited for a -30C night in the driveway?

Furnace oil and No.2 diesel are one and the same product except furnace oil has a little dye in it.

Diesels will run nicely on a wide variety of fuels.
Kerosene
Jet A
JP-8
Vegetable oil (Herr Doktor Diesel intended it to use peanut oil)
Used motor oil (cut it 20:1 with No.2 and filter it)
Propane
Butane
White gasoline
Alkane synthetic diesel (Fischer-Tropsch)
Transesterified biodiesel

The Germans have built diesels that start on No. 2 and then run bunker C until hot then run on pulverized coal.

High octane (low cetane) gasoline defeats them unless you use the No.2 injectors as spark plugs.

great idea, but more polluting
 

Your idea of using furnace oil or "red diesel" is outstanding. It is cheaper, but I am not sure if it would pass for emissions testing. One difference is that it more polluting and has a higher amount of sulfur than LSD: 500 ppm and ULSD: 15 ppm. However, if it's easier on your pocketbook then why not!?!?

Be aware, the "red" is red diesel is dyed specifically so that tax agents can tell it is diesel that has not been properly taxed for road use. If you get caught you'll have the IRS down on you very quickly. I know people have been caught many a times before, and with fuel prices being so high I'll be willing to bet they've stepped up their enforcement.