Ask yourself these seven questions to make sure your fuel quality program is working for you.
By Peter J. Cochefski
New high-performance diesel engines are required to meet higher emissions and efficiency standards while also having a longer service life. These modern diesel engines require clean, high-quality fuel to operate properly, making them sensitive to fuel contamination.
It’s important to maintain fuel storage tanks with proper tank inspection and cleaning methods and procedures. A clean underground or aboveground fuel storage tank (UST/AST) ensures that clean fuel will always be ready for use by fleet vehicles, which reduces costs and the downtime associated with engine breakdown and repairs.
But what must tank operators know about fuel quality and how to ensure it’s not compromised? There are seven questions you must be able to answer if you are a fleet operator or a marketer.
Why Is Fuel Quality So Important?
Fuel represents approximately 60% of a truck fleet’s total operating costs.
With fuel prices increasing, the impact that fuel expenditures can have on a company’s bottom line is reason enough to prevent fuel from becoming contaminated. Poor fuel quality and the use of contaminated fuel can result in premature wear, engine failure or, at minimum, decreased engine performance that will reduce efficiency, leading to higher fuel consumption rates.
Unfortunately, the quality of today’s fuel has not kept up with the advances in engine technology. With today’s tight tolerances of vehicle fuel-injection systems and high-pressure fuel pumps, engines are susceptible to having their performance affected by the impurities that can be found in today’s fuel.
What Are the Costs of Low-Quality Fuel?
A clean fuel storage tank ensures that the highest quality of fuel is ready for use in company vehicles. Not only does high-quality fuel keep trucks on the road, but it also reduces the costs and downtime that can be associated with engine breakdown and repairs. A fleet that is plagued by breakdowns and idle trucks can have an immediate and overwhelmingly negative impact on the company’s bottom line. Water, microbial growth, corrosion, sunlight and high temperatures can all influence the speed of diesel fuel degradation, putting pressure on the fleet operator to ensure that only in-spec fuel is entering the fleet’s fuel tanks.
My Fuel Has Become Contaminated … Now What?
The most significant quality issue with today’s fuel is the intrusion of dirt and water into USTs and ASTs. Comprehensive sampling and site inspections are specifically designed to analyze the condition of in-tank fuel based on a customized, predetermined set of customer specifications. It’s important to control and detect fuel contamination, whether it’s particulate, chemical or some level of water intrusion. Vehicle fuel systems can be damaged and rendered out of service if these contaminants are allowed to enter the system. Therefore, it’s best to deal with these contaminants before they are transferred to the vehicle’s fuel tanks.
Tank operators should not wait to clean tank bottoms until they are experiencing slow flows and frequent filter changes at the fuel island. As sludge accumulates in the UST/AST, it can become very dense or calcified. In these situations, the tank owner needs to have the tank physically cleaned by way of manned entry. This cleaning can cost the owner many thousands of dollars in expensive services and downtime. USTs and ASTs should be inspected and cleaned at least once annually to prevent the effects of water, particulate and microbial fuel contamination.
Fuel tank cleaning is a necessary component in a successful UST/AST management program and can be one of the most important things a fleet owner or operator can do to keep their fuel supply up to code and performing properly. Over time, repeated filling makes fuel storage tanks susceptible to the accumulation of particulates and moisture. Making sure that fuel tanks are properly cleaned and maintained will improve the vehicle’s fuel economy and result in longer engine component life. In addition to reducing the frequency that fuel filters will need to be changed, clean fuel prolongs fuel injector life, resulting in a more efficiently operating vehicle.
What this all comes down to is vehicle availability. When vehicles are not in the maintenance bay, they are at work. Less downtime means greater productivity.
How Significant a Problem Is Microbial Contamination?
While fuel quality can be impacted or compromised at any point along the distribution chain, the fueling site’s storage tanks are the last link in the supply chain before the fuel is introduced into a vehicle. They are also potentially the point at which the fuel sits the longest before being transferred or used.
A clean fuel storage tank ensures that the highest quality of fuel is ready for use in company vehicles. Not only does high-quality fuel keep trucks on the road, it reduces the costs and downtime that can be associated with engine breakdown and repairs. Idle trucks can have an immediate and overwhelmingly negative impact on the company’s bottom line.
When it comes to fuel storage, today’s more expansive range of fuel formulations presents many challenges for the tank operator. One of the most significant is that new fuels, such as ultra-low-sulfur diesel (ULSD), are more prone to experiencing contamination. Most contaminants are typically introduced into fuel during the transportation, delivery, mixing/blending or storage processes.
Water, which is the most common contaminant, may be introduced when moist air condenses on the fuel tank walls and condensation builds up within the tank, with this water working its way into the fuel mixture. Excessive levels of water can reduce the lubricating qualities of fuel, which can cause fuel injector seizure and engine damage, which will sideline the vehicle while costly repairs are performed. In addition, fungi and bacteria live in water. When these organisms enter a fuel system, they can affect sensitive rail injectors in diesel engines and plug fuel filters, reducing their life and causing premature wear, all of which affect life expectancy and overall on-road vehicle performance.
Particles of dirt, sediment and other solids have a similar effect on fuel injectors, causing them to wear out prematurely, leading to costly engine or fuel-system failures. Today’s high-pressure rail injectors, which are standard components on most heavy-duty, diesel-powered transport trucks, are especially vulnerable to clogging from contaminants.
Do Filters Really Matter?
Fuel dispenser filters are the last line of defense, the final opportunity to control fuel quality before any contamination is transferred into a vehicle’s fuel system. Dispenser filter design and function are fairly specific to the fuel type and require knowledge of the fuels being delivered and dispensed in order to ensure the most trouble-free engine operation.
There are several variables that can increase the frequency of filter plugging. A few of the most common are contaminant levels that have become problematic in the UST/AST; tank wall deterioration caused by age or misuse; microbial growth and microbe byproducts; recent use of a biocide without cleaning the tank; switching from regular fuel to an ethanol blend; and poor tank maintenance. If filters are plugging at a higher-than-expected rate, the contaminated fuel is that much closer to entering your vehicle fleet or the customer’s automobile, and that much closer to damaging your business’s reputation.
As part of a successful preventive maintenance program, filters should be changed whenever their flow rate dips below optimal levels. The National Conference on Weights and Measures, which sets standards that states may choose to adopt, allows a minimum of a 30-micron filter at the dispenser. Some fleets that operate their own fueling systems find fuel-related damage to vehicles from hard particles as small as four microns in size, suggesting that a 30-micron filter adds little protection to a modern diesel engine. This is likely due to the fact that Tier 3 and Tier 4 engines are typically equipped with 10-micron prefilters and two-micron fuel filters, so diesel fuel with particulates that exceed the ISO rating dispensed through a 30-micron filter places the burden of fuel protection squarely on the engine’s fuel filters. Also, overly restrictive filters can come with potential flow-related challenges that will need to be evaluated by each tank operator before a filter type is ultimately selected.
What Are Some Tips to Improve Fuel Quality?
The best approach is to remember a tried-and-true saying: “An ounce of prevention is worth a pound of cure.” In other words, tank operators must be proactive when it comes to fuel quality. Waiting for a problem to occur before acting is a sure way to compromise the ability of your fleet to meet the needs of your clients. The most important preventive step is keeping the amount of water in storage tanks as low as possible, preferably zero. A proactive fuel-maintenance program that includes frequent fuel sampling, fuel polishing with microfilters and coalescers, and annual UST/AST tank cleaning is the most effective way to keep stored fuel clean and free of contaminants.
What Are the Benefits of Clean Fuel?
Developing and sticking to a proactive fuel-quality program is the best way for fuel suppliers and tank operators to keep their vehicles running and their clients happy. By committing to a program, fuel suppliers and tank operators can expect the following benefits:
- Decreased fuel costs
- Reduction in harmful emissions
- Decrease in microbial bacteria and fungus infestation
- Longer mean time between filter changes
- Increased service life for fuel systems and engines
- Reduced downtime and loss of income due to fewer fuel-related vehicle breakdowns
- Greater and quicker return on investment
Peter J. Cochefski is the director of Ryder Fuel Services, a subsidiary of Ryder System, Inc. He can be reached at (305) 676-2105, ext. 822, or [email protected]. For more information, please visit ryder.com.
