Diesel Fuel Additive

Did I read a while back about adding something to the current low sulphur diesel fuel for pump lubrication? Or does today's fuel work on these older (60s and 70s) diesels?

vegetable oil

It's not a matter of "working" or "not working." It's a matter of shortening the overall life of mechanical rotary injection pumps that aren't used on newer vehicles. Many farm tractors though, as well as Chevy/GM SUVs and trucks, Ford trucks up to mid 1994, Dodge trucks with Bosch rotaries, etc.

If you have an in-line injection pump, it's not an issue. An in-line pump actually has a separate injection pump for each cylinder and no distributor to worry about. It is the distributor that causes the big problems with low-lube fuel.

The new fuel does not have the same lube as the old fuel did. When the sulfur is cooked out of it, lube is lost. As a result, lube additives are put back in before it gets to the pump, but that will vary and still does not bring the new fuel up to the same lube level of the past.

A well cared for mechanical rotary pump can last 1,000,000 miles. It may get sent back to the shop for so-called rebuilds 3-6 (more or less) times, but often all the major moving parts are use over again, as is.

So, I suspect most people will never know when their pump life was shortened - unless they know it's actually new inside and then goes bad in short order.

For a non-emissions car, truck, or diesel tractor using two-stroke-oil at a 1 to 400 ratio gets the lube up to where it ought to be and it's usually the cheapest/effective additive. I buy it in gallon jugs at Walmart. I only use it on my highway diesels. For my tractors, I use medium sulfur dyed off-road fuel that does not have the low-lube issues - yet. But I'm in NY. In some parts of the USA, dyed fuel is ultra-low and DOES have the issues.

NO "snake oil" is needed.

Biodiesel

power source from walmart,anti gell and lubricant.

Stanadyne does not agree with you.

Yep,

The emperior has no clothes and he's really pizzed off that the little "secret" is out. :>)

Allan

What Bob said below.

Can't believe that people actually buy into these marketing "scams". It's total BS.

Kinda like 'gasket sealers' 'deer whistles' and the famous 'energizing braclet'. :>)

Allan

Not sure what exactly that is all supposed to mean.

Stanadyne has published recommended lubrication specs for their rotary distributor injection pumps. The new ultra-low sulfur fuel is a bit below those specs since it is not required for new electronic injection systems. When it first came out it was very low. Now it is required to put lube additives put into it before it gets to the pump. With that additive it still a bit lower then the requirements for the older rotary pumps.

I don't have a lab to test fuel lube nor do I have a lab to conduct metal wear tests on injection pumps. I DO try to stay well read on the subject and read tests done by companies that make fuel and these pumps. For now, I'll take Stanadyne's word for it. Also the same from the US military that has had miserable problems with rotary pumps used with JP8 low-lube diesel fuel.

There have also been tests done for any possible gains with "snake oils" as some put it. Two-stroke-oil is at the top of the list for the "best bang for the buck." Very cheap investment when used at a 1 to 400 ratio.

I call it cheap insurance for a very expensive injection pump. And, others call it "snake oil." I guess we are all free to believe what we want.
I try not to guess at such things when I don't have to.

Cite some hard facts please, such as . .

minimun lube specs from CAV and Stanadyne for distributor injection pumps

minimum lube requirements for ultra-low diesel in the USA

If you are saying this is nonsense . . then please . . why don't you and Bob enlighten us all.

Same goes for highway motor oil for autos and trucks made since 2009 that lacks the lube requirement for many engines with flat tappets and camshafts.

Here are a few specs for lube additives and what seems to be the best buy - which in my area is gallon jugs of Walmart two-stroke-oil.

Diesel fuel and other fluids are tested for lubricating ability using a device called a “High Frequency Reciprocating Rig” or HFRR. The HFRR is currently the Internationally accepted, standardized method to evaluate fluids for lubricating ability.

It uses a ball bearing that reciprocates or moves back and forth on a metal surface at a very high frequency for a duration of 90 minutes. The machine does this while the ball bearing and metal surface are immersed in the test fluid (in this case, treated diesel fuel). At the end of the test the ball bearing is examined under a microscope and the “wear scar” on the ball bearing is measured in microns. The larger the wear scar, the poorer the lubricating ability of the fluid.

The U.S. standard for diesel fuel says a commercially available diesel fuel should produce a wear scar of no greater than 520 microns. The Engine Manufacturers Association had requested a standard of a wear scar no greater than 460 microns. That is also what Stanadyne recommends for many rotary distributor injection pumps.

Southwest Research Laboratory did a test on types of lube additives.

Walmart Super Tech Outboard 2-cycle TC-W3 engine oil
(Not ULSD compliant, may damage 2007 or newer systems)
HFRR 474, 162 micron improvement when added at a 200:1 ratio

Stanadyne Lubricity Formula
HFRR 479, 157 micron improvement
Added at a 1000:1 ratio

Amsoil Diesel Concentrate Multi-purpose
HFRR 488, 148 micron improvement
Added at a 640:1 ratio

Power Service Diesel Kleen + Cetane Boost
HFRR 575, 61 micron improvement when added at a
400:1 ratio

I obviously did not write this but I DO find it interesting. Perhaps Alan and Bob will not.

The Ultra-Low Sulfur Diesel (ULSD (S-15)) that we started to receive in mid 2006 has shown some dramatically different cold weather characteristics from the earlier High Sulfur (HSD (S-5000)) and Low Sulfur Fuels (LSD (S-500)).

These new characteristics including higher temperature gelling, wax dropout, icing, and difficulty in treating have in the first year and will continue into the foreseeable future to provide some significant challenges to distributors and end users during cold weather.

Due to these new characteristics users in areas of the US where they have not seen cold weather problems in the past, are now and will continue to see serious issues with gelling, wax dropout, and icing.

Here are the main issues known today:

Wax in diesel fuels – Paraffin wax is a natural and important part of diesel fuel. This wax provides several beneficial characteristics including high energy content (Btu’s), lubricity, stability, and viscosity. The negative characteristics mainly revolve around cold weather operation and include gelling and something new we refer to as wax dropout.

In HSD and LSD the wax characteristics were relatively well understood and consistent. For example the “Rule of Thumb” used for adding kerosene (#1 diesel, Jet A) to #2 fuel to lower Cold Filter Plug Point (CFPP) was that for every 10% kerosene added to #2 diesel you would lower CFPP by approximately 5°F. An example would be that a 50% blend would have improved CFPP by about 25°F.

However the new ULSD has had several important characteristics changed by the new refining processes. The catalytic cracking and hydrodesulfurization processes remove some of the wax, it alters the size and shape of the wax seed crystals in the fuel, lowers the aromatic content of the fuel, removes a significant amount of the Lubricity, and lowers the fuels ability to dissipate static electricity by as much as 100 times.

The result of this is that the ULSD fuel actually will gel at a higher temperature than the old LSD and HSD. This problem is made more difficult because we can no longer use regular kerosene (#1 diesel, Jet A) for cold weather blending. These fuels are considered High Sulfur and their use would cause the end fuel to have sulfur content higher than the allowable 15 ppm. So refiners have had to create an ULSD #1 specifically for winter blending purposes.

There are a number of problems with this new fuel. First, it is currently very expensive, ranging anywhere from $.30 to $1.00 more than regular kerosene, second it is not available in all areas, and third this new ULSD #1 is not as effective at lowering the Cloud Point (CP) and CFPP (gel point) of the fuel. For example; ULSD #2 when blended with 10% ULSD #1 will lower the CFPP by only 2°F or maybe 3°F. This means that a 50% blend would only improve CFPP by 10°F.

To make this problem even more difficult, many of the diesel fuel anti-gel additive products that have been on the market for last 5 to 30 years have little or no effect on ULSD. The change in fuel chemistry brought about by changes in the Catalytic Cracking processes and the addition of Hydrodesulfurization have rendered many of the most popular products nearly useless in ULSD.

There is a new cold weather problem that the industry has not adequately defined
as of today. We are calling this issue “Wax Dropout”. Wax Dropout occurs when diesel fuel is “cold saturated”. This where the fuel reaches a given temperature and stays at or below that temperature for a given period of time. This time period is usually between 48 and 72 hours or longer and the temperature can vary with different batches of fuel. This past winter we saw this problem at between 5°F and 10°F.

When the fuel gets to the Wax Dropout temperature, say for example 8°F and stays there for 48 to 72 hours, the wax will suddenly agglomerate and fall to the bottom of the container. This wax plugs filters and fuel lines until it is removed or until the fuel temperature is raised to a point where the fuel will reabsorb the wax.

Again there is a further complication, in that the “old” HSD and LSD wax would gradually start to reabsorb as the fuel temperature rose. With ULSD when wax dropout has occurred the wax does not begin to reabsorb until the fuel reaches fairly high temperatures, often above 40°F, 50°F or even higher. This can make the process of getting an engine with gelled fuel to run properly far more challenging than we have ever seen before.

In the fuel distribution and fleet operations businesses, we have relied on CFPP as
a measure of winter fuel quality for many years. CFPP is a fairly complicated test involving using a vacuum to draw a sample of fuel through a 45 um (micron) screen within a given period of time.

When the HSD and LSD were most prevalent and most fuel filters were 10 um there was a good correlation between CFPP and the temperature at which a standard fuel filter would plug. For example you could be relatively certain that a fuel testing for CFPP of -25°F would provide trouble free operation to -15°F to -20°F.

However the relationship is much different with ULSD. A ULSD fuel testing
-25°F CFPP might have filter plugging problems at between -5°F and -10°F. Also CFPP does not seem to be directly related to Wax Dropout. A fuel can test for
-15°F and still have Wax Dropout at 8°F.

Furthermore, OEM engine manufacturers have changed the media size of their fuel filters. Where 10 um has been almost an industry standard, we now see 7 um, 5 um, and even 2 um filters today. This throws the whole relationship between CFPP and winter operability out the window. For example fuel that is at the CP can have filter plugging problems with a 2 um fuel filter.

The industry has not yet agreed on or developed testing methods to measure cold weather operability with the new fuels and filters.

Until such time as the industry develops a test method for determining the relationship between CFPP, PP, Wax Dropout, and filter media size for ULSD, we suggest the following: For 10 um filters; Take the midpoint between PP and CFPP, for 7 um filters, take the midpoint between PP and CFPP, then take the midpoint between that number and the original CP, for 5 um and 2 um use the CP.

Water is more of a problem than ever before. Diesel and biodiesel fuels hold
water dissolved in them. The amount of water that ULSD is able to hold is greater than that of HSD or LSD. One of the characteristics of fuel is that its ability to hold water in solution diminishes as the temperature decreases. Fuel delivered at 70°F with 200 ppm of dissolved water will as the temperature drops begin to push that water out of the fuel into droplets. These droplets can be seen floating in the fuel and as temperatures reach and go below 32°F those droplets freeze becoming ice crystals.

As a result many of the cold weather problems where people believe they have fuel gelling problem are actually a fuel icing problem. If you have operability issues in temperatures above 0°F you should check to be sure that you aren’t dealing with ice.

Customers are regularly reporting situations where they have no water in storage tanks, no water in vehicle or equipment tanks, but they constantly have water in filters and separators. This is due to the dissolved water falling out of solution due to temperature changes.
Diesel Doctor
Copyright 2009©


Elemental Metals (ASTM D-5185) – Elemental analysis identifies any contamination by another fluid such as engine oil, coolant, etc. It also can identify corrosion problems.

Cetane Index (ASTM D-4737) – Calculated according to ASTM D-4737, using API Gravity and mid-boiling point, the Cetane Index is a measure of a diesel fuel's ignition quality – similar to an Octane rating for gasoline. The minimum Cetane Index for #2 diesel fuel is 40.

Viscosity @ 40°C (ASTM D-445) – Viscosity is the measurement of a fuel's resistance to flow at a given temperature. When viscosity is out of specification, fuel injector performance may be affected.

Distillation (ASTM D-86) – Distillation determines initial boiling point and separation of distillates at different temperatures, identifies dangerous or damaging gasoline contamination and helps verify levels of kerosene added during winter months.

Water & Sediment (ASTM D-2709) – Water and sediment can clog fuel filters and cause significant power loss, corrosion, fuel system component wear and promote microbiological growth.

Thermal Stability (ASTM D-6468) – A fuel's thermal stability is represented by a percentage range that is based on its tendency to produce asphaltenes at high temperatures. Asphaltenes are tar-like, resinous substances most often responsible for clogging fuel filters. Fuel with a thermal stability of 80 percent or greater should not cause filter clogging. Fuels between 60 and 80 percent could have a marginal affect and values less than 60 percent will significantly reduce filter life.
Bacteria, Fungi & Mold – The presence of bacteria, fungi and/or mold indicates that fuel storage tanks have not been properly maintained. When present, water separates from fuel and accumulates at the bottom of storage tanks creating an excellent breeding ground for biological growth.

Sulfur Content ppm (ASTM D-2622) – Determining sulfur content confirms compliance with the EPA's requirements of <15 ppm (parts per million).

HFRR Lubricity (ASTM D-6079) – This test determines whether or not a fuel meets the lubricity requirements needed to maintain maximum injector performance and can also be used to monitor appropriate lubricity additive formulations.

Pensky Marten Flash Point (ASTM D-93) – This test determines if the fuel will burn at the proper temperature.

Water by Karl Fisher (ASTM D-1744) – Water by Karl Fisher measures water by titration and is reported in either parts per million or percent by volume. It takes water & sediment one step further by determining how much water is present.

API Gravity (ASTM D-287 ) – API gravity determines fuel density and, along with distillation, is used to calculate the Cetane Index.

Cloud Point (Winter) (ASTM D-2500) – Cloud point determines at what temperature wax crystals first begin to form – gelling will clog fuel filters.

Pour Point (Winter) (ASTM D-97) – Pour point determines the temperature at which fuel will no longer flow. Winter additives or pour point depressants lower pour point to extremely low temperatures to prevent gelling.

During the winter season, all Midwest low sulfur No. 2 diesel fuel from Marathon-supplied terminals will have a maximum cloud point of +10° F.

Just put a new gas tank in mmy pickup.A sheet that came with the tank said warranty applied up to 5% biodiesel or up to 20% ethanol gas.