Diesel is a petroleum-based product made from hydrocarbons. A distillation process that separates out crude oil also produces diesel. The diesel blend is widely available throughout the world.
Diesel engines are favored for their high torque output, efficiency and reliability. Their main advantage is high thermal efficiency, which gives better fuel economy over gasoline engines. Diesel engines are the dominant engines in trucking and are extensively used in shipping.
According to the Diesel Fuels Technical Review by Chevron, written in 2007, ultra-low sulfur diesel has been widely used in Western Europe and Japan since 2005 and in the United States since 2006. As of June 1, 2007, refiners began producing low-sulfur diesel for railroad locomotives.
Marine diesel engines must meet stringent emission requirements. In May 2004, the Clean Air Non-Road Diesel Rule was introduced, which set out to decrease sulfur content by 99%. The Clean Air act began to go into effect in 2007.
