Cleaner diesel fuel, advanced engines and effective emissions control technology make up a new generation of diesel. It's clean diesel.
What is clean diesel?
What makes it different from regular diesel?
Clean diesel is the new generation of diesel made up of a three-part system that combines cleaner diesel fuel, advanced engines and effective emissions control technology. This new system ensures that clean diesel engines will continue to play a dominant role in the future while helping meet energy security, greenhouse gas and clean air objectives around the world.
Clean diesel fuel - containing 97 percent less sulfur - is now the standard for both on-highway and off-highway diesel engines nationwide. Using this ultra-low sulfur diesel (ULSD) immediately cuts soot emissions from diesel vehicles and equipment by 10 percent. Reducing the sulfur content of diesel fuel is similar to removing lead from gasoline during the 1970s.
Cleaner diesel fuel enables the development of a new generation of advanced engines and emission control devices that can't operate effectively with higher sulfur content in diesel fuel. This three-part clean diesel system enables emissions reductions of over 95 percent from vehicles and equipment.
Why is diesel technology so fuel efficient?
A combination of the energy-rich properties of the fuel, and the efficiency and completeness of the combustion of fuel to create useful mechanical energy. Diesel is a petroleum-based fuel with the highest energy density among transportation fuels - that's more energy per gallon than other alternatives. The U.S. Energy Information Administration states that few transportation fuels surpass the energy density of diesel.
Read DTF's Diesel Fuel Study - Diesel: Fueling the Future in a Green Economy.
Diesel is the world's most efficient internal combustion engine. It provides more power and more fuel efficiency than alternatives such as gasoline, compressed natural gas or liquefied natural gas. Read more about the history of the diesel engine.
Fuel combustion is the primary difference between gasoline and diesel engines. Gasoline engines ignite fuel with spark plugs, whereas diesels ignite fuel with compression. Inside the engine, the combustion of air and fuel takes place under pressure and heat created by compressing the air-fuel mixture so intensely that it combusts spontaneously, releasing energy, that is transmitted to powering the wheels on a vehicle, the piston's motion and creating mechanical energy.
Advanced new technologies such as electronic controls, common rail fuel injection, variable injection timing, improved combustion chamber configuration and turbocharging have made diesel engines cleaner, quieter and more powerful than past vehicles.
Introduction of ultra-low sulfur diesel fuels for both on- and off-road applications has been a central part of the new clean diesel system designed to meet near zero emissions standards. With the introduction of lower sulfur diesel fuel, a number of exhaust treatment systems such as particulate filters, exhaust gas recirculation (EGR), selective catalyst reduction (SCR) and diesel oxidation catalysts (DOC) can further reduce emissions from diesel engines. The installation of various emission control technologies may also improve emissions from older diesel engines through retrofit capabilities. Read more about retrofit capabilities to reduce emissions from older vehicles and equipment.