JP4 vs Diesel

[MAragorn]

I have a friend who has a friend (no, really) who flies a helicopter for a living. As I understand it, they have to test the fuel very often and then have to discard the fuel pulled for the test. They generate a couple of hundred gallons of clean, waste JP4 fuel each month. Until now they have been paying to have this disposed.



My friend has been asked if he wants the fuel. They will pay him to take it. They told him that JP4 is a highly refined diesel and that they sometimes used it in diesel vehicles, but they no longer have these.



I drive a 2003 Dodge with the Cummins diesel. Do you know if this fuel can be used safely in my truck?



Thanks for the help

 

[evelrod]

No.

Rod

 

[GregLocock]

JP4 is more like kerosene than diesel. Its cetane number (ability to ignite) is half that of the minimum spec for diesel.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[reidh]

Greg is correct about JP4 and the cetane number.

However, I have run both JP4 and JP8 in my '86 Volkswagen Golf Diesel without any problems. I was given the car for free, which is why I didn't hesitate to experiment with free fuel (Maragorn: I am in a similar situation as you, in that I can obtain the fuel for free). I always mix it with Diesel from a gas station, and never put in more than half a tank of the military fuel. I had some concern about the reduced lubricity of the JP4 and JP8, but it has not had a noticeable effect on the driveability.

I should also say I am not performing an engineering test here. I have not opened the engine to see the effects of this mixed fuel, or done any other tests to quantify the effects of the alternate fuel.

That being said, would I run it in my 2003 Dodge Truck if I had one? Never!

-Reidh

 

[rmw]

I don't drive anything diesel right now, but if I did, I wouldn't hesitate to mix it into the diesel in limited quantities. #1 Diesel used in the northern USA in the winter is a blend of diesel and kerosene, but it is not used in warmer climates. I probably would limit it to about 20% of the total fuel, but at that ratio I'd burn the heck out of it.

rmw

 

[TheBlacksmith]

Part of the highly refined part is the removal of all wax compounds that could solify (freeze) at high altitude and stop the turbines. This lack of wax is very hard on diesel injection components. They use jet fuel (JP-5) in small boat engines in the Navy as these boats are outside on deck and have to start, even in February in the North Atlantic. This practice was carried over to 80 foot boats (GM 71 series) with heated engine rooms that ran every day. I had them change to diesel fuel and the rate at which we went through injectors was cut to 10% of that on JP-5.

 

[SomptingGuy]

In the UK this practice (using un-taxed fuel on the road) would be also illegal.

 

[evelrod]

Running jet fuel in a 'freebie' diesel might be fine as long as you keep your cell phone handy. Nuts, IMO.
Run it in my Dodge...not a friggen chance, mate!

SG...It's illegal in the states, too. Even 'home brew' bio diesel is illegal, technically. As a kid, our untaxed, 'farm' fuel had a purple dye added and if you got stopped and they found 'purple' the fines were quite high...having said that, I never even heard of anyone getting cought and fined during those years I used it (1950's).

Rod

 

[reidh]

I am veering a bit off topic now, but bio-diesel, JP4, or any fuel can be legal as long as you pay the transportation tax here in the states. Although there may be good reasons not to run fuels other than those specified by the manufacturer, legality shouldn't be one of them.

-Reidh

 

[swall]

Correct me if I am wrong, but isn't the U.S. military running JP-4 in most of their diesel land vehicles?

 

[reidh]

I know they are using it for air vehicles and some tanks (specifically M1 Abrams, which is turbine powered).

Per the military specification, HMMWVs(Humvees) are allowed to run on JP4, JP8, Diesel, DF2, or VV-F-800. In the current combat situation, HMMWVs are filled with whichever of these fuels is most convienent and plentiful, as running fuel convoys is a dangerous mission these days.

-Reidh

 

[thruthefence]

Years ago I used to know a guy who ran 'sump' jp4 in his old Mercedes all the time. I was told that the trick was to dump a cup of automatic transmission fluid with each 10 gallons of JP, to provide lubrication for the injectors. Apparently jet fuel has all the parifin (which acts as a lubricant)refined out, due to it's tendency to clog fuel filters at high altitude.As has been noted, this is 'no road tax' fuel, thus illegal.Here at the airport, some ground support equipment runs on JP, and the fuel farm has a special seperator that cleans the sump 'test' fuel for that purpose.

 

[evelrod]

Reidh.
"...legality shouldn't be one of them."

In an ideal state, I agree. However, yesterdays newspaper the Alcohol Beverage Control unit arrested two elderly women at the local Lake Elsinore Elks lodge for participating in a $50 football pool!!!

Perhaps paranoia is setting in after all these years. In dealing with our current administration in DC, all bets are off!

Rod

 

[SomptingGuy]

I always thought that the military need was "one fuel for all". Understandable really, given the overhead of multiple fuel types.

 

[Fabrico]

Lubrictiy, or the lack of it, was a concern with the ultra-low sulfur Diesel fuel being used in the states. It turned out not to be a problem.

 

[IceStationZebra]

I was involved with a Military contract to supply the Marines with an off-road forklift. We were required to demonstrate that it ran on JP-8, which is basically civilian jet fuel JetA/JetA-1 with an antifungal additive. It was my understanding from several ex-military co-workers (several who worked on tanks and other large machines) that the military runs diesel on base because it is cheaper, but wants the ability to run JP-8 during wartime (or should that be conflicts? ). JP-8 was not good for diesel engines until they started hard coating (chrome?) the fuel pump pistons and other high pressure parts ~15 years ago.

We did not have to run on JP4, which is basically kerosine. You can probably get away with cutting it into summer fuel, but you will experience more smoke and less power. I wouldn't go above ~20%.

ISZ

http://en.wikipedia.org/wiki/Jet_fuel

 

[swall]

Actually, a problem has been reported in the media about the low sulfur fuel. A school bus fleet in Pennsylvania was down due to jelling of the fuel in the subzero weather we have been experiencing in the midwest. The new fuel was named as the culprit. I can't see how removing the sulfur changes the jelling point of the fuel.

 

[dicer]

Fabrico (Automotive) 8 Feb 07 19:22

Lubrictiy, or the lack of it, was a concern with the ultra-low sulfur Diesel fuel being used in the states. It turned out not to be a problem.


SomptingGuy (Automotive) 8 Feb 07 16:09
I always thought that the military need was "one fuel for all". Understandable really, given the overhead of multiple fuel types.

You guys are right on.

 

[WGJ]

SAE 2007-01-0002 has details on a comparison between diesel fuel and kerosine in a single cylinder test engine.


Bill

 

[IceStationZebra]

swall - could the bus deal have been related to bio-diesel? I remember hearing a story that Minnesota tried to push bid-diesel onto consumers last year (or the year before?) with a lot of stranded vehicles when the first cold snap came. Maybe they had a contaminated fuel supply? I can't explain why ultra-low sulpher would gell any more than low-sulpher, otherwise you would have heard a big stink from all of the semi truck drivers.

Lubricity was also the big concern when we switched from "normal" to low sulpher fuel many years ago. I was too young to remember much, but from what I've heard it was a big learning curve regarding hard finishes, tolerances, etc.

ISZ