How Clean Is Your Diesel Fuel?

Not that many years ago, compact equipment ran on diesel fuel that was inexpensive, easy to store in bulk and performed well year-round. So why did it change?

Although diesel fuel was much simpler and less sensitive to contaminants, its byproduct was targeted by clean-air officials in their effort to reduce hazardous air pollutants that were linked to chronic health conditions and harmful to the environment.

In 2010, to combat this air quality issue, the United States Environmental Protection Agency (EPA) mandated that ultra-low sulfur diesel (ULSD) become a requirement for all U.S. diesel engines. Nearly all compact equipment manufacturers now use advanced engine technologies—designed with high-pressure, common-rail (HPCR) systems and sophisticated fuel injectors—to burn cleaner fuel and comply with nonroad emission standards set by the EPA.

Fuel costs can be among the largest operational expenses for construction business owners.

It is important to follow these recommended fuel best practices to help reduce machine downtime and costly injector-plugging from water, debris and other contaminants often found in diesel fuel.

1. Purchase fuel from the best possible supplier

Good fuel management starts with purchasing clean, dry fuel that is properly blended for the climate. You may have to pay more for clean fuel, but investing in quality fuel will give you better peace of mind, lower your fuel consumption, make fewer fuel filter changes necessary and deliver longer component life. Verify the fuel’s cleanliness by asking key questions, including: “What micron level of filtration is used on your line?” and, “Is this the best fuel available for the current climate?” A good fuel distributor will provide diesel fuel that meets all of the specifications for most climates and environments.

2. Confirm the fuel’s cloud point

Diesel fuel was previously produced with sulfur levels as high as 500 parts per million (ppm). However, today’s ULSD is produced with sulfur levels less than 15 ppm. This significant reduction in sulfur content was necessary to lower emissions, but the process used to remove sulfur also increases saturates, which, in turn, increases the fuel’s cloud point.

Cloud point is defined as the temperature where wax begins to drop out of fuel, creating a translucent appearance. The wax forms crystals, ranging from 50 to 200 microns in size, which can quickly plug your machine’s fuel filter. Ask your diesel fuel supplier to confirm the fuel’s cloud point, since it is dependent on the geographic location and the time of year that fuel is intended to be used. For example, fuel available in North Dakota during September will have a different cloud point than fuel available in Texas in July.

3. Prepare for cold weather

Today’s diesel fuel chemistry has made it harder for diesel fuel suppliers to consistently provide fuel that performs well in cold climates. However, you can utilize cold-weather practices, including removing trapped water from your machine’s fuel filter daily, maintaining a machine’s battery state of charge, installing an engine block heater and choosing the best engine oil and hydraulic/hydrostatic oil for the current temperature conditions.

In addition, fill your machine a higher percentage of winter blend diesel fuel and begin using it earlier in the season. Operations in cold and northern regions should use a special winter-blend fuel—typically No. 1 and No. 2 diesel fuel—to prepare the machines for cold temperatures. It is beneficial to maintain a cold-weather kit, purchase cold-weather accessories and to follow cold-starting procedures as outlined in your machine’s operation and maintenance manual. Be sure to read it thoroughly to learn about cold-starting procedures and further minimize machine downtime.

4. Test bulk fuel tanks every 6 months

Water and other contaminants can impact fuel chemical structure and eventually lead to pump, filter and injector problems. That is why it is important that either you or a professional diesel fuel-cleaning and inspection service test your supply tanks for water or other contaminants in your storage tank every 6 months. If you decide to test fuel, there are a variety of fuel testing and analysis kits to measure the cleanliness, percentage of water, cloud point and several other categories. Typically, small amounts of water can be removed, but if significant amounts of water or sludge are found, the entire storage tank should be drained and cleaned.

5. Keep supply tank fuel filters clean

How do you know whether a 5- or 10-gallon plastic container is contaminant-free? To help prevent contaminants and increase the effectiveness of the machine’s fuel filter, make sure any fuel entering a storage tank passes through a dispensing filter. In addition, fuel tank filters should be capped and the tank should have a 1-micron vent filter. Tank filters typically have a 10-micron-or-finer filter to filter free and emulsified water to help ensure the highest quality fuel for your equipment.

6. Use 2-micron fuel filters

Some fuel filters chosen for HPCR engines can trap down to 2-micron contaminants, helping remove free and emulsified water. Although no filter will remove all contaminants, using the cleanest fuel possible and using an efficient fuel filter can help minimize the amount of particles entering the machine. It is also important to consider the following best practices:

• Drain the water trap daily.
• Never prefill a new filter during installation.
• Never open fuel connections in the system upstream of the fuel filter.
• Use the manufacturer’s recommended replacement fuel filter.

It is also best to purchase an extra fuel filter for every Tier 4 HPCR-engine-equipped machine and keep it on the jobsite in case contaminated fuel is used in a machine and the filter needs to be replaced on-site.

7. Fill machine tanks at the end of each workday

HPCR engine technology generates higher fuel temperatures, and as the machine cools, condensation can form in air gaps. Make sure every machine is filled with diesel fluid at the end of the workday in order to prevent potential condensation and reduce maintenance costs.

8. Attend a fuel management clinic

Compact equipment dealers should understand how today’s diesel fuel is different and how it relates to advanced engines so they can treat fuel-related issues. Your dealership may decide to host fuel management clinics to accurately relay those tips to you and your operators. Try to attend these clinics to learn more about this important topic.

9. Keep a preventive maintenance log

Finally, you and your machine operators should keep a preventive maintenance (PM) log that includes maintenance history, refill/supplier history, filter replacements and fuel particle counts. A PM plan can help reduce machine downtime and cut down on costly injector-plugging from water, debris and other contaminants found in diesel fuel.