#2 Diesel vs JetA1

[whizznbyu]

I met a pilot who has access to Jet A1 and he told me that the sulfur content is higher, and that it is more energy dense than diesel. I had to do my own investigation and there are different websites with different opinions.
I was intrigued by what this pilot told me he did with this JetA1 fuel. If Jetfuel has a higher sulfur content, then it follows that ULSD has a lower sulfur content than JetA1. If there are additives out there to increase "lubricity" does it follow that Jet A1 has better lubricity given its higher sulfur level?

 

[turbobrick240]

No, Jet A , and all jet fuel has terrible lubricity- extremely dry. It is also substantially less energy dense than diesel fuel. I think jet a is low sulfur now too. I know heating oil and off-road diesel are. If you can get free jet fuel and want to use it in a diesel engine, I'd mix it with 5% biodiesel to put some lubricity into it.

 

[ghohouston]

Some atf would probably suffice. I knew someone who used nothing but jet a on two 7.3's for over 200k between both trucks, and never had problems. I think they used two stroke oil as a lubricity additive.

 

[IndigoBlueWagon]

What worked in an old Powerstroke without any emissions hardware to speak of doesn't indicate it won't cause issues in a 2015 TDI. What you save in fuel you may well spend in repairs.

 

[ghohouston]

What worked in an old Powerstroke without any emissions hardware to speak of doesn't indicate it won't cause issues in a 2015 TDI. What you save in fuel you may well spend in repairs.

Didn't see where it said a '15 model (I use this forum on my phone and unless I turn it sideways, signatures are not displayed) but you're right and I agree. I wouldn't hesitate to run it in any pre dpf engine, as long as some lubricity is added.

 

[rocky raccoon]

In my previous life, I was involved in converting a PG84(class) Navy patrol gunboat into a high speed research vessel. The ship had an LM1500 gas turbine bypass engine, two cruising Diesels and a Diesel housekeeping engine. It was designed to use JP4 (or JP5, I forget which) to run the gas turbine and the Diesels. We wanted to convert to Diesel for all engines including the gas turbine mainly for fuel availability issues wherever we went.

The conversion was simple, mainly additional filtering since Diesel is "dirtier" than JP and it has more water content by transportation specification than the JP. The same fuel pumps and nozzles worked well for both fuels. The conversion was successful and two such vessels were put together and operated out of Panama City Florida, Athena and Athena II.

Interestingly (to me anyway) the boats were faster on Diesel than on JP. The reason given was that Diesel is sea-level fuel and more energy dense than the JP. Lubricity of course was not a problem.

 

[turbobrick240]

Quite a lot of military vehicles are multi-fuel capable. For logistical reasons, pretty much all US main military vehicles (in theatre anyhow) these days run on JP8. They even have diesel dirt bikes/motorcycles that burn jet fuel. I'm not sure what, if anything, they do about lubricity. Wouldn't be surprised if they add some motor oil or hydraulic fluid though.

 

[dieseldonato]

Quite a lot of military vehicles are multi-fuel capable. For logistical reasons, pretty much all US main military vehicles (in theatre anyhow) these days run on JP8. They even have diesel dirt bikes/motorcycles that burn jet fuel. I'm not sure what, if anything, they do about lubricity. Wouldn't be surprised if they add some motor oil or hydraulic fluid though.

With the advent of lsd and ulsd most manufacturers had changed to better and harder moving parts in the fuel systems. I remember when ultra low sulfur diesel hit mainstream, injection pumps and injectors had a high rate of failure in older engines. Once rebuilt with better component the issues went away. Military equipment is also built with multi fuel use in mind. I know deere and cat had military specific features that commercially available machines did not. Couldn't tell you which were fuel specific, but the deere low heel loaders did have a set of filters specific to the military units, and supposedly one of the filters had something to do with adding lubricity back into lower quality fuels.

 

[turbobrick240]

I know some heavy equipment feeds used, filtered motor oil into the fuel system as a sort of continuous oil change. I assume there's a decent sized reservoir for fresh oil to keep everything topped up.

 

[dieseldonato]

Don't know of any equipment mfg that currently do that. Roadway used to do something like that with their trucks. Perpetual oil changes. Spin a filter on every x miles and top the oil off every Y hours. With emissions how they are now (off road is tier 4 final, just like on road) I'd think it's not really an option anymore, or at least not a good option with common rail and other high pressure injection options.

 

[[486]]

Interestingly (to me anyway) the boats were faster on Diesel than on JP. The reason given was that Diesel is sea-level fuel and more energy dense than the JP. Lubricity of course was not a problem.

look no further than the density specification
kero is less dense than diesel which is less dense than heavy oil

Engines inject by volume, so...

 

[[486]]

Quite a lot of military vehicles are multi-fuel capable. For logistical reasons, pretty much all US main military vehicles (in theatre anyhow) these days run on JP8. They even have diesel dirt bikes/motorcycles that burn jet fuel. I'm not sure what, if anything, they do about lubricity. Wouldn't be surprised if they add some motor oil or hydraulic fluid though.

the old multifuel m35 trucks they advised you to add motor oil to the fuel when burning gasoline
but not so with kero/jet

 

[turbobrick240]

Don't know of any equipment mfg that currently do that. Roadway used to do something like that with their trucks. Perpetual oil changes. Spin a filter on every x miles and top the oil off every Y hours. With emissions how they are now (off road is tier 4 final, just like on road) I'd think it's not really an option anymore, or at least not a good option with common rail and other high pressure injection options.

Yeah, DPFs probably wouldn't like that. But a lot of that heavy equipment has a long service life- I'm sure there are quite a few still out there operating.

 

[Thunder Chicken]

I burnt lots of jet in a ‘96TD, and a ‘04TDI. When I upgraded to the ‘12CR TDI, I gave up using Jet. I’m deleted and still wouldn’t use it, mixed or not. It’s too dry and the thought of a fuel pump issue makes it not worth it. Maybe with a CP3 pump? I dunno….. I also have a tractor with a commonrail engine and I won’t use it in that either, I have access to an unlimited amount of Jet A1….. I should have an oil furnace in my garage……

 

[turbobrick240]

Quite a lot of excess Jet A was blended into diesel stocks during the height of the COVID outbreak. Jet A is basically kerosene with a sprinkling of additives. I think a 95% jet/kero , 5% FAME biodiesel blend would be safe in even the less robust CP4 commonrail diesels, but probably wouldn't want to be the guinea pig for that theory, lol.

COVID-19: Use of excess jet fuel in automotive diesel fuel affects lubricity additive response - Multisol

Lockdowns resulting from the COVID-19 pandemic have had far reaching impacts across the transportation industry and, with the aviation sector being particularly hard hit, refiners are blending surplus jet fuel into automotive diesel fuel. Infineum’s Paul van Munster, Technical Lead, and Dean...

multisolgroup.com

https://www.researchgate.net/publication/229210996_HFRR_lubricity_response_of_an_additized_aviation_kerosene_for_use_in_CI_engines

 

[[486]]

or just cut it 50:50 with used motor oil

let it sit a while in your drums and keep your pump a foot off the bottom of the drum and you won't even need to filter it because all the particulate drops out as sludge, just run a screen to catch all the floaty stuff like dead flies that'll block the pickup in your sending unit

 

[John Wesley Hardin]

I met a pilot who has access to Jet A1 and he told me that the sulfur content is higher, and that it is more energy dense than diesel. I had to do my own investigation and there are different websites with different opinions.
I was intrigued by what this pilot told me he did with this JetA1 fuel. If Jetfuel has a higher sulfur content, then it follows that ULSD has a lower sulfur content than JetA1. If there are additives out there to increase "lubricity" does it follow that Jet A1 has better lubricity given its higher sulfur level?

I once saw a panhandler standing on a street corner in West Palm Beach FL. dressed quite well with his sign saying. "Will work for Jet Fuel"

 

[BamaB4S]

I use this forum on my phone and unless I turn it sideways, signatures are not displayed.

Thanks for the useful tip!

 

[John Wesley Hardin]

or just cut it 50:50 with used motor oil

let it sit a while in your drums and keep your pump a foot off the bottom of the drum and you won't even need to filter it because all the particulate drops out as sludge, just run a screen to catch all the floaty stuff like dead flies that'll block the pickup in your sending unit

I thought you had to use a centrifuge to run used oil. How long does it take for metal particles to settle and wouldnt you run 1 micron filters for added filtering?

 

[John Wesley Hardin]

I thought you had to use a centrifuge to run used oil. How long does it take for metal particles to settle and wouldnt you run 1 micron filters for added filtering?

I have access to all the free WVO and used motor oil I need at no charge . But am hesitant to use it . I would in the case of social chaos. However I know my neighbor runs straight filtered WVO from the same source in his Dodge dually and VW diesel wagon. Just filters it and dumps it straight in the tank with diesel. No separate tank to heat it

 

[[486]]

I thought you had to use a centrifuge to run used oil. How long does it take for metal particles to settle and wouldnt you run 1 micron filters for added filtering?

VE/VP pump? I have no idea about PD or CR motors.

nah, filtering is a waste of time, stock fuel filter is 23 micron, I've plugged several solid, injectors and pump are still just fine. You do end up with a lot of fuel contamination in your crankcase oil so I would not run veg oil.
You also don't want a finer fuel filter, unless you've got a lift pump they're just too much of a restriction even when you're running clean fuel, makes your timing advance operate all wonky

 

[John Wesley Hardin]

VE/VP pump? I have no idea about PD or CR motors.

nah, filtering is a waste of time, stock fuel filter is 23 micron, I've plugged several solid, injectors and pump are still just fine. You do end up with a lot of fuel contamination in your crankcase oil so I would not run veg oil.
You also don't want a finer fuel filter, unless you've got a lift pump they're just too much of a restriction even when you're running clean fuel, makes your timing advance operate all wonky

So you run used motor oil in a TDI or similar without pre filtering ?

 

[[486]]

So you run used motor oil in a TDI or similar without pre filtering ?

Of course not, if you do that the tax man is allowed to nail your doors shut, set fire to your house and shoot your children as they run from the fire.

 

[John Wesley Hardin]

Of course not, if you do that the tax man is allowed to nail your doors shut, set fire to your house and shoot your children as they run from the fire.

And when you dont want your young children to learn about Transgenders and butt sex in elementary school they do the same