Today we have a new generation of electronically controlled, low emission, high speed and high horsepower diesel engines. The reason for all this new technology is the need for diesel engines to meet the clean air acts of 1998 and 2002. They are accomplishing this by using electronic injectors and by changing the diesel fuel we are presently using.
With this new generation of diesel engines you need to take precautions to properly maintain the engine. This includes installing a proper fuel / water separator along with using a proper fuel additive designed to meet the challenges for today’s electronic engines. If you take these precautions it will save you costly down time and money.
First, a proper fuel/water separator ( SEPAR FILTER ) must remove all of the dirt and water in the fuel. The reason for this is that the injector tolerances on the electronic engines are smaller then the old style injectors. The new injectors will not tolerate any water in them at all. This is why you want to use a fuel additive that removes the water from the fuel (demulsifies) to get any emulsified water out of the fuel. Do not use a fuel additive that emulsifies the water into the fuel. Next the filter has to flow more fuel with less restriction through the fuel system. The reason for this is, the new style engines flow about 2-3 times more fuel in order to cool the electronic components. With this larger fuel flow you are allowed a maximum fuel pump restriction of 4.1 to 12.0 inHg depending upon the engine manufacturer. Most of your fuel / water separators will not meet these standards because they were never designed for today’s engines and fuel flows.
We also wanted to share our observation with you on the fuels you are buying today. They are different from the fuels you were buying in the past. Diesel fuel today is so dynamic that even today, as we speak, decisions on what color to make what diesel products are still being argued over between the EPA, IRS, API and the rest of us.
In order to understand the 1994 version of diesel fuel we must go back to the 1970's. As a result of a growing demand for middle distillates, which include kerosene, jet fuel, #1 and #2 diesel fuel, refineries no longer simply distilled crude oil to make distillates, they resorted to catalytic cracking. The difference between light, middle, and heavier fuels is the boiling ranges. The cat-cracking process breaks up heavier fuels so they will meet the specifications for the lighter products, the refineries made the investment to catalytically crack more crude. Today’s heating oil and diesel fuel that you buy are the product of severe catalytic cracking. So what does this mean? Fuel that has been refined this way doesn’t want to stay in its new form. It wants to change back into something heavier. The heat of an engine raises the temperature of the fuel in the return lines, thereby accelerating the formation of particulates. In fact any energy that we put into today’s diesel and heating oil (regardless of sulfur content) speeds up the production of solids. These solids take many shapes and forms. They are typically sticky gums, varnishes and sludges that will plug filters, strainers, nozzles, and injectors. Often we blame bacteria for these solids, when in fact this is just the fuel re-organizing itself into heavier products that like to stick together. In fact 93% of what clogs today’s filters is not dirt or algae, but it is the repolyermerization of the fuel. The microscopic particulates that form will grow larger and eventually clog your fuel system.
And then came October 1, 1993, low sulfur fuel was born. Reducing sulfur is good for both the air we breath and for the post combustion components of an engine. Sulfur forms a load bearing protective film that will be missed. This will result in the premature failure of injectors, injector pumps, and the balance of the fuel metering system.
One major change we missed on October 1, 1993, was the change to a calculated cetane index number of 40, rather than a minimum engine cetane number of 40. Very simply stated the refiner now provides us with a slightly lighter cut of fuel to achieve the calculated index rather than use a cetane improver. The difference is a light fuel that has less BTU’s per gallon. Less BTU’s equals lower mileage and power. Lighter fuels entrain more water and are less lubricating.
Heating oil for off road purposes is being overlooked. Low sulfur diesel is certainly being scrutinized by many. The other #2 product is not. Cetane numbers on the higher sulfur off road fuel are often in the 37 or 38 range. Cetane numbers only give you ignition. There are typically more BTU’s in off road fuels. However our concern here is overall fuel quality is suffering from lack of quality control because we are all so distracted by low sulfur fuel.
The good news is that for each of the deficiencies of 1994's fuel there are materials that can be added to minimize the problems while maximizing the performance of your equipment:
- Catalysts will improve power and miles per gallon.
- Lubricity agents will reduce premature failure of injectors and pumps.
- Stabilizers will stop gum and particulate formation.
- Biocides will stop bacteria and fungus.
- Cetane improvers (when absolutely necessary).
Besides changes in the way fuels are being processed we are also seeing changes in the way fuel is being stored. We used to store fuel underground where the fuel was always cool. Today you are seeing above ground fuel tanks. This causes higher storage tank temperatures and accelerates the formation of particulates produced by the fuel. This means more condensation as the tank “breathes” during the changes in the atmospheric pressure or temperature.
So with the changes in the diesel engine, the processing of the fuel and the way the fuel is being stored, you need to look at new ways of testing, filtering and treating your fuel. If you do not take these precautions it could be an expensive mistake. Price a new style injector and pump and you will see the importance of proper maintenance.