Running 2008 6.4 L Super Duty PowerStroke on off-road diesel?

[TeejT]

I am curious if anyone knows if it's okay to run a 2008 6.4L PowerStroke truck on off-road (farm) diesel for off-road operation (I'm aware that it's illegal on-road). I'm wondering whether technically the off-road (higher sulfur) diesel wears out or damages components of these engines.
Thanks in advance!

 

[TheBlacksmith]

I believe it will "poison" or chemically inert the exhaust particulate catalyst simialr to how leaded gasoline destroyed catalytic convertors. The replacement cost would probably pay for the difference in fuel cost for hundreds of gallons.

 

[BrianPetersen]

Off-road diesel could be identical to on-road diesel (ULSD) except for the dye, or it could be something other than ULSD, which will damage the DPF system. The problem is that you normally don't know. I wouldn't take the chance.

 

[patprimmer]

How hard would it be to remove the DPF system also when off road and running off road diesel.

Regards
Pat
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[j2bprometheus]

Pat-

Removing the DPF is illegal---

Also, the engine may have a two-way catalyst uptream of the DPF. A two-way catalyst would be poisoned by high sulfur but would probably recover after some high load operation.

Re-installing the DPF is probably a hassle since things are likely to be hard to reach. Keep in mind that your time is worth money too.

The turbine for that engine was selected based on the restriction in the exhaust caused by the DPF system.

Removing the DPF would lower the exhaust restriction.

This would probably make the turbine seem too "small" for the engine, thus affecting the performance. Conditions near rated power would be most affected.

The bottom line: just use on-highway diesel fuel. The savings in fuel cost is unlikely to be worth the effort / risk.

j2bprometheus

 

[MikeHalloran]

You'll never get all the dye out of the system, so subsequent on-road use will get you in trouble.



Mike Halloran
Pembroke Pines, FL, USA

 

[patprimmer]

He does not actually say whether or not he ever intends using it on road again. This could have a significant impact on the decision.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

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for site rules

 

[rmw]

Wouldn't the reduced pressure of the exhaust system make the engine seem like it was too small for the turbine?

You also have to think about injection pump parts and injectors.

I don't know if the inverse is true, but when the sulphur was removed from diesel, the older stuff that depended on that for lubrication suffered. Now that pumps and injectors have been designed to operate without the lubricity, would the addition of sulphur be detrimental. I don't know. Just a thought.

And... the above assumes that OR diesel has more sulphur than ultra low sulphur over the road diesel.

The most salient point above was the one about never getting the dye completely out if you ever wanted to go back to operating over the road. Lots of farmers who have tried to do it both ways have learned the hard way that they can't get away with that.

rmw

 

[TeejT]

patprimmer,
I would have intended to use it on-road again. Just off-road while on work sites (for days at a time). It's looking like a non option, but that is good to know. Thanks.

 

[evelrod]

"Off road for days at a time"....How many miles do you accumulate in this off road time? My old Dodge/Cummins gets ~22mpg and on a 30+gal. tank and my son's newer Dodge gets 24/26mpg on a ~35gal. tank, that's a lot of "off road", even for "days at a time"!

Saving a few bucks per tank in tax is about all the benefit I see and that's certainly not enough to warrant all the mods mentioned unless you are "possessed". I wouldn't do it even if the fuel was free...but that's me.

Oh, by the way, I'm a country boy that has used non taxed fuel over the years. In the time frame of the 1950's to the late 1980's I have never even heard of anyone getting gigged for the much feared "red/purple die" problem. Perhaps the gov't is better at policing road tax problems these days?.....LOL

Rod

 

[TheBlacksmith]

First of all, it's not the sulfer that protects the injectors. The most economical method of removing sulfer also strips lubricity, that is the problem with ULSD. I did a lot of research for my current project on this subject. And yes Rod, at least here on the east coast, where the states are hungry, they want their fuel tax and will check the trucks for untaxed fuel.

 

[mikehoncho]

If you delete the DPF/DOC, you should be able to run offroad diesel without any issues. The offroad dye will not last long once you run one or two tanks of road diesel back through it.. Just run it low on offroad before you refill it. The DPF removal only takes a couple hours in your driveway (if you buy a kit) and is reversable if you save the parts. You will need a tuner or some custom flashing to shutoff the REGEN cycle from your ECM. Don't try to run it with only the exhaust mod. You have to reprogram it or it won't run right.
It will feel like you pulled cork out of your tailpipe when you get done.

 

[Gearloose1]

I am not so sure about how long off-road dye last.

During the Katrina / Rita crisis, when the US had to go to emergency measures to keep fuel available in the affected areas, one thing that was permitted (for a while) is running dyed diesel in on-road trucks.

Problem is, people were getting caught years later with the dye in their filters / tanks.. and getting fined.

Apparently a lot got off on the defense that they legally used off-road then.

---------------

Insofar as the DPF, it is not just a DPF, but also a catalyst

http://green.autoblog.com/2007/10/23/ford-clean-diesel-6-4-liter-power-stroke-doesnt-compromise/

There is a Diesel Oxidation Catalyst built in.


Once you use fuel with high levels of sulfur in it, it is nearly impossible to get it out of the fuel tank / engine / lubricating oil.

 

[drwebb]

I understand on-road diesel fuel has a minimum lubricity performance specification. So unless one believes the industry spec is inadequate, the presence or absence of sulfur should not be a concern for that aspect of fuel performance.

 

[Gearloose1]

Regardless of sulfur content, lubricity specs for on road diesel have to be met.

Insofar as whether the spec is adequate, there are two issues:

A) whether in fact the spec is met in real life samples (as there is no actual auditing / sample testing of most fuels sold)

B) if the spec is itself adequate

Many people out there tend to believe both issues are problems, and go to the trouble and expense of buying additives to put in diesel fuel.

 

[evelrod]

My old Dodge is at something close to 300,000 miles I suspect, with no problems (knock wood) using commercially available fuel in the Western U.S. I'm not positive about the mileage, it could be more as the odometer broke in 1998 at 186,000 miles !!!
I've never used an additive...the Cummins runs just fine and still gives the same fuel consumption rate as it has since I bought it new in '91. Based on my experience I'd say the fuel anti wear additives that replaced the higher sulfur content must be doing it's job.

Rod

 

[Gearloose1]

There was a lot of issues switching over from LSD to ULSD in terms of deposits build on EGR components, which may / could have also come from the rampant use of sub-standard biodiesel which is widespread (even today) and home brews.

Around mid 2000s with diesel prices exploding, many people were running home brew biodiesels that is nothing more than filtered used french fry oil and expecting their vehicles to work.... with finely tuned emissions systems, DOCs, and EGR.

One immediate problem that have been hinted at (but haven't seen much published) is when fuel went from LSD to ULSD or to biodiesel (of any % blend above say, 2%), what effect does it have in leaching stuff that is in the system, including corrosion products, varnish, etc.?

What about damage to seals that were not designed for it?

As it turned out, engines that were in the installed base from mid-2000s onward to 2010 had a lot of issues, including EGR clogging with particulates, that seem to have completely gone away recently once the system had a cleaning / replacement of bad EGR components within the past year.