Pros and Cons of Clean Diesel

Clean Diesel

It’s been almost a decade since the US Environmental Protection Agency adopted more stringent requirements for diesel fuels. The idea was to reduce diesel emissions and diminish the production of black carbon particulate matter.

Ultra-low sulfur diesel (ULSD) fuel has been required since 2014 for all diesel uses including on-road vehicles, off-road agricultural, construction and transportation equipment, and stationary facilities that burn diesel to generate heat or energy. A range of outcomes—some are good, some are bad and some were unanticipated—have been produced from the push for truly clean diesel fuel as a viable power source.

Pros of Clean Diesel

ULSD fuels are more stable and contain 97 percent less sulfur than conventional diesel. This is good, because when fuels containing sulfur are burned they produce sulfur dioxide, a contaminant that can irritate the lungs and contribute to the formation of acid rain and ground level ozone. Additionally, the USLD refining process destroys other organic compounds that contribute to particulate matter (PM), so ULSD assists in reducing sulfur-based and PM pollutants.

Cons of Clean Diesel

The ULSD production process, unfortunately, also destroys compounds that reduce gum formation, so most ULSD must be treated with a stabilizer to discourage gummy deposits that clog fuel injectors and fuel filters. This fuel is also a less effective lubricant, which increases wear on engine components such as fuel injectors and pumps.

ULSD costs more because it is more expensive to produce and these costs are passed on to users, contributing to higher prices for everything from fuel and food to goods, services, heat and energy. In addition, ULSD produces 1 percent to 2 percent less energy than its predecessors, so it takes more fuel to travel a defined distance, complete a specific task or produce a product.

Clean Diesel Cautions

Ironically, some studies state the superfine particles produced by ULSD and advanced emissions control systems may actually contribute to respiratory issues and impaired breathing, creating more serious health effects in the long run.

The devices used to reduce diesel vehicle emissions are extremely sensitive to even lower levels of sulfur, and continued exposure to sulfur causes permanent damage and necessitates expensive repairs.

ULSD attracts and holds moisture, which contributes to corrosion, freezing and microbe growth. Metal components found at every stage from refinement and transport to storage and vehicle engines are especially vulnerable to corrosion. The higher water content can cause ULSD to freeze at comparatively mild temperatures as well.


Clean diesel fuel is a mixed blessing. Combined with advanced engine designs and emission technologies, it’s helped improve air quality. It has also introduced complications ranging from increased costs to unexpected performance problems and the need for additives to increase lubricity, reduce water retention and improve fuel flow in cold weather. For more information about clean diesel, contact us here at Asher Automotive with the link below!

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