Oil & Fuel Darker exhaust from new diesel fuel?

[teachdocs]

I have noticed a significantly darker exhaust from both of my Kubota diesel engines in the past couple of weeks. Could this be from the recent changes in the diesel fuel or biodiesel?

I notice it the most upon start-up until the engine has warmed up for about 10 minutes and then when under a heavy load. Much different than before.

I have always used Power Service diesel additive. Would it maybe help to use more or less?

 

[azhfl56]

I didn't think we were using the newer (cleaner) diesel yet. It doesn't make sense that it is burning dirtier, it should be cleaner. Maybe it is due to lower quality diesel at the fuel station. I have a diesel Jetta and some tanks don't get the mileage that I should, I chalk that up to the fuel. I always get it at the same place and I think quality control is less stringent on Diesel fuel than gasoline. Just my two cents worth. Check the air filters also.

 

[N80]

I noticed that on my L4400 I get a little black puff at start-up. It has always done that. The only other time I get any black stuff is when I put it in 4-high (top gear) and take off down the paved road. Right when I give it gas to take off it gives a single black puff. This seems like a newer thing. The tractor has about 75 hours on it.

I don't think anything is wrong since it works just fine, but I do wonder why I'm seeing this now. I've been using more 'off-road' diesel than before but I wouldn't think that had anything to do with it.

 

[SkyPup]

All of our Kubota diesels always have a puff of black smoke on startup and when under extreme load, always have and always will, since that is the only time they are running too rich. Other than that, have noticed no difference besides a little different smell.

 

[sandman2234]

The new fuel that your talking about may be seeping into your tanks as we type. It is mandated that Diesel be available by Oct 15 with less than 15 ppm sulfur. The mainstream fuel usage is current burning "Low Sulfur Fuel" which is 500 ppm sulfur. The new fuel is going to be called "Ultra low sulfur fuel".
To determine which fuel your buying, you should be able to look at the pump. It is mandated that the pump be marked for which fuel they are selling. However, if they have extra "Ultra", and they want to sell it as just "Low", they can because it meets the requirements. However, it is more expensive to refine, so not much of that will be going on.
The place you will get the Ultra sold as Low, will be as they mix the new in the tanks with the old, which contaminates the Ultra, so it will be sold as Low. If they have problems with a batch at the refinery, you can bet it will be sold as "low sulfur", not ULSD.
The ULSD phase in, required 80% of diesel refined or imported in this country to be 15ppm max, as of June 1. Good sources say that was probably closer to 90/10 or a little more than 90% being ULSD.
You can pretty much bet your likely to have some, or have it soon.
David from Jax

 

[tony3542]

I've noticed some stations here in middle Tennessee have a sign that says off road diesel available here.Does that mean its not the low sulfur ?
thanks
tony3542

 

[Toolguy]

There are some good threads on the new diesel fuel over on the fuels and lubricants form. I learned a lot from it. The new ULSD is already in the tanks at the stations and has been for a while. The suppliers need to make sure all of the low sulphur fuel is flushed out of the system. It has all of the necessary lubricant additives so it should have no different effect on the way any modern diesel runs. It is required for the 2007 models in order to meet emissions standards. I notice you said that you have been running off road diesel. That is a high sulphur blend that has been outlawed for on-road use for years. Th off-road is dyed red to identify it from the low sulphur on-road blend. It will work just fine in your tractor. If you can find it it will be cheaper because the road taxes are not added to the price. As far as the smoke you are getting, I have no clue unless it is from the off-road fuel. You also said something about Biodiesel. Are you running that, too.

 

[MadReferee]

I notice you said that you have been running off road diesel. That is a high sulphur blend that has been outlawed for on-road use for years. Th off-road is dyed red to identify it from the low sulphur on-road blend. It will work just fine in your tractor.

Close but no cigar. In most areas of the country off-road has been the same blend as on-road, only with the dye added. With the switch to ULSD and the very limitied availability of LSD (500 ppm fuel), just about everyone will be selling dyed ULSD as their off-road offering because that is all they will be able to get. LSD (500 ppm fuel) will probably become more expensive as it becomes scarcer and scarcer due to the small amount of it being refined.

ULSD will work just fine in your tractor.

I've noticed some stations here in middle Tennessee have a sign that says off road diesel available here.Does that mean its not the low sulfur ?

It most likely means that it is dyed and no federal and/or state road tax has been applied. As to the suplhur content it may be LSD or ULSD. You have to check at the pump.

All of the above DOES NOT APPLY TO CALIFORNIA. In California all you can get is ULSD for any application, on or off-road.

 

[lanschuetz]

Close but no cigar. In most areas of the country off-road has been the same blend as on-road, only with the dye added. With the switch to ULSD and the very limitied availability of LSD (500 ppm fuel), just about everyone will be selling dyed ULSD as their off-road offering because that is all they will be able to get. LSD (500 ppm fuel) will probably become more expensive as it becomes scarcer and scarcer due to the small amount of it being refined.

ULSD will work just fine in your tractor.

It most likely means that it is dyed and no federal and/or state road tax has been applied. As to the suplhur content it may be LSD or ULSD. You have to check at the pump.

All of the above DOES NOT APPLY TO CALIFORNIA. In California all you can get is ULSD for any application, on or off-road.

Maybe I'm all wet, but I have a theory on this. I too buy off-road diesel
to avoid the 60+ cent/gallon PA road tax. Works fine - recommended to
me by the local tractor repair guy I bought my 'bota from. But, this last
container full does seem to smoke a bit more and have a little less
"oomph" - not so much that to be readily measureable, but different.

So my theory is that we are now getting the last dregs of the LSD
tanks as all refineries clear out old inventory. That would tend to be
more highly contaminated with both water and, well, crud. My
understanding is that it *all* has to be ULSD going forward.

Might prove myself wrong if things continue this way in the next few
months - or just that my B6200 is showing it's age - but then so am I
Just my $0.02 - your mileage will probably vary.

 

[MadReferee]

So my theory is that we are now getting the last dregs of the LSD tanks as all refineries clear out old inventory. That would tend to be
more highly contaminated with both water and, well, crud. My
understanding is that it *all* has to be ULSD going forward.

Well, that's always possible. You should ALWAYS filter your diesel fuel before putting it into the tractor tank. A Mr Funnel is a good tool for doing that.

LSD will still be available in some portions of the country for another few years. However only small refiners are allowed to make it so it will not be available everywhere and will probably be a little more expensive.