Both diesel fuel and regular unleaded gasoline are primarily made up of petroleum and are used to run different types of engines. Diesel fuel, also known as petrodiesel, is produced with a hydrocarbon mixture from the distillation of crude oil. On the other hand, regular unleaded gas contains aliphatic hydrocarbons that increase the fuel's octane rating. Regular gas is also usually mixed with ethanol, while diesel is not. Diesel fuel is considered a combustible, which means it uses pressure and heat to run an engine. Unleaded gasoline is a flammable, meaning it requires a spark to operate an engine.
Diesel fuel is an oil-based substance, making it much denser than regular gas and causing it to evaporate at a slower rate than unleaded gasoline. In general, diesel fuel is considered more fuel-efficient than regular unleaded gasoline. Diesel fuel typically contains more sulfur than regular gas, which causes it to release more greenhouse emissions when burned by a car engine. In addition, automobiles that run on diesel fuel are expected to perform worse than unleaded cars in cold-weather conditions.
In the United States, most cars are built to run on regular unleaded gasoline. However, many large trucks and buses still rely on diesel fuel. In terms of other forms of transportation, diesel fuel is usually the most popular type of fuel used. Most modern railroads no longer use steam-powered locomotives. Instead, the electric locomotives of today run on diesel fuel. Additionally, many aircrafts are powered by diesel engines.
