Oil & Fuel When does diesel gel?

[daTeacha]

I had to laugh when our local paper said diesel gels at 20F. They went on to talk with local school superintendents who said the wind chill was low enough to gel diesel, showing a lack of understanding of wind chill on their part.

I've heard different things for when the stuff actually gets too thick to flow, ranging from the laughable +20F above to -40F. My tractor seems to run fine at -7F, with no fuel line heaters or anything, so if anyone can give an accurate figure, it would be nice. The custodian here at school, an old farm boy, said he adds a quart of gasoline to a tank of diesel to prevent problems. I didn't get to follow up on whether he meant a storage tank or a vehicle fuel tank, but I presume it's the former.

 

[MadReferee]

Answered very eloquently in This Thread.

 

[JoeL4330]

I am sure the old timer referred to adding gasoline to the tank ...used to be an alternative recommended by engine manufacturers ...discussed in the owner's manual of my MB 180D ...but adding "engine kerosene" is/was preferred ("engine" kero presumably means kero w. road tax, where applicable)...the addition of gasoline is highly discouraged nowadays, as is use of ether ...neither is happy with some forms of engine/fuel pre-heat. I don't recall the ratio of gasoline to diesel fuel, but it was small. Diesels don't like "anti-knock" so the lower the octane the better. All in all, forget the gasoline, use winter blend or no. 1D, consider white power service before kero, keep power service "911" on hand for emergency, along with new fuel filter(s) ...on my kubota, the fuel tank is situated above the engine and so is naturally heated once the engine is running and up to operating temp ...and, it is shielded from wind, which might take that heat away too fast (wind chill ...which only makes the effects of cold work faster, but once the engine is "cold soaked" it doesn't matter ...to the engine, that is)

If you have a problem even once the engine is running, investigate an aftermarket fuel filter/heater ...racor makes them as do others.

The only other point is that the more "winterized" the fuel, the less specific energy, so you get less horsepower-hours per gallon.

 

[DieselPower]

Personally I would never add gas to diesel fuel. It would probably do more harm than good by lowering the lubricity of the fuel.

What is the gel point of diesel fuel? No exact answer and depends on to many variables. What type of crude oil was it refined from, what additives did the distributor add to the fuel, was it cut with #1 kero or diesel fuel, etc...

 

[Egon]

[school superintendents /QUOTE]

Hey; they are administrators, why should they be knowledgeable about Physical facts.

They just might be competent in other fields.

 

[FARMALL RON]

When it get's cold ...........RON

 

[cp1969]

I used to have a pipeline transporter's brochure that said the cloud point for #2 was +12F which isn't that far from your +20F figure.

Whether or not that will stop your engine depends on more than just the cloud point of the fuel, though. The porosity of the fuel filter will play a role...a 2 miron filter is going to plug much sooner than a a 10.

 

[john_bud]

When does diesel gel?

Usually about 60 seconds after you turn to your wife and tell her how great your diesel truck does in cold weather. It's cut down to 30 seconds if you are in a hurry and down to 15 seconds if it's for an appointment for her and you turned down using her gasoline powered car for your diesel truck.

jb

 

[RalphVa]

Adding gasoline to diesel is very dangerous. The typical add rate was 10%. At this amount, the amount of gasoline vapor (actually butane) in the tank is just right to provide an explosive mixture. In a typical gasoline tank this mixture is too rich to promote explosion.

The only time I ever had diesel gel was at -22 F in Vermont. With a radiator hose heater run for about an hour ahead of time, the car started instantly (after the required glow plug time). About 3 miles down the road, it died. I let it sit a minute or so and restarted it. Another 3 miles or so, it died again. Again, after sitting a minute or so, it restarted. It was obviously fuel wax gelling in the fuel filter, which is mounted right on the engine block in all Benzes. Sitting for a little bit next to the block melted the wax enough for it to flow again. After a while, heat from the block kept the wax melted that was flowing into it.

I was using not additive at that time nor adding any kerosene. Typically, Vermonters added 30-50% kerosene to their diesel in the winter time.

The new ULSD diesel will probably have a little bit more wax in it, due to processing that turns some of the multiring sulfur compounds into broken paraffinic chains.

Ralph

 

[daTeacha]

I'm running off road diesel in the tractor and haven't had any problems. The old B7100 would get hard to start (think two batteries in series backed up by two battery chargers) in the cold, but once started it ran fine on fuel from this same source. I guess I should check the sulfur content, but I don't think it's even rated LSD.

Interesting discussion on the referenced thread. I presume my source, which moves an awful lot of diesel to farms, schools, OTR trucks, county trucks, state trucks, city trucks, etc. is stocking and selling winterized fuel. Our district closed out of concern for the kids waiting at the bus stop on windy mornings, not due to worry about the buses running.