Diesel vehicles emissions encompasses global policy perspectives such as CO2, a global warming gas and local criteria pollutant emissions which are potentially harmful to human health along with degrading local air quality. RD fueled diesel vehicles built before 2007 model-year do exhibit lower criteria pollutants-as stated previously. However, RD fueled 2007 model-year and newer vehicles criteria pollutants are generally not changed when fueled with RD. RD fuel used in these newer engines do benefit with better performance and RD cleaner burning attributes help maintain lower criteria pollutant emissions over their useful life. All HD RD vehicles (using pure RD fuel) derive CO2 reductions that at a minimum, match HD EVs CO2 reductions. In California due to the state’s LCFS Program the 2019 blended RD / diesel fuel sold had 14.5% lower CO2 than conventional petroleum diesel. Pure RD is sold in several retail stations in California, this fuel has 68% lower CO2e per gallon and per mile driven than petroleum diesel in 2020.[1]
If you want to know more, please refer to Stillwater Associates’ Gary Yowell’s article, How Do ZEV Emissions Stack Up Against Super-Clean Gasonline and Diesel Engines?
The Diesel Engine.
The history, present and future of the compression ignition engine, is a fascinating story that spans over 100 years, from the time of Rudolf Diesel to the highly regulated and computerized engines of the twenty-first century. The development of these engines provided inexpensive, reliable, and high-power density machines to allow transportation, construction, and farming to be more productive with less human effort than in any previous period of human history. The concept that fuels could be consumed efficiently and effectively with only the ignition of pressurized and heated air was a significant departure from the previous coal-burning architecture of 1800s. Today, the compression ignition engine is undergoing yet another revolution. The equipment that provides transport, build roads and infrastructure, and harvests the food we eat needs to meet more stringent requirements than ever before. (U.S. Department of Energy Office of Science)
Diesel fuel is the second largest transportation fuel used in California, representing 17% of total fuel sales behind gasoline. According to the state Board of Equalization, in 2015 4.2 billion gallons of diesel, including offroad diesel, was sold.
Nearly all heavy duty-trucks, delivery vehicles, buses, trains, ships, boats and barges, farm, construction and heavy duty military vehicles and equipment have diesel engines. Diesel is the fuel of choice because it has 12% more energy per gallon than gasoline and has fuel properties that prolong engine life making it ideal for heavy duty vehicle applications. In 2006 ultra-low sulfur diesel was nationally introduced allowing for near-zero heavy duty diesel engines sold since 2007 model-year. Biodiesel was introduced into California in 2000 and Renewable Diesel in 2012. While Biodiesel and Renewable Diesel use the same feedstocks, Biodiesel is predominantly made from soybean and recycled oils into a unique diesel fuel. Renewable Diesel is predominantly made from animal waste oils and the finished fuel is nearly identical to petroleum based diesel.
In conclusion, California continues to rely on a portfolio of fuels and vehicle technologies to meet our transportation needs and fuel our state’s economy. We believe diesel technologies will remain a key component of that portfolio by continuing to provide near-term energy benefits as well as helping to maintain our long-term energy and environmental goals.
