Vehicles have been running on gasoline for decades, but in recent years, manufacturers have been building vehicles that are able to run on alternative types of fuel. Here are some of the most popular:
Ethanol is produced by fermenting biomass – most commonly, corn. Because it’s a renewable resource, it produces no greenhouse gas emissions. When ethanol is used to fuel vehicles, it can be blended with any amount of unleaded gasoline, though usually it’s a blend of 85% ethanol and 15% unleaded gasoline. This mixture is called E85.
Hydrogen is not a renewable resource, but can be created by altering natural gas or by using electricity to split water into hydrogen and oxygen. If it’s created using electricity from a natural resource (like wind power or solar power), then it won’t produce any type of pollutant when used to power a vehicle.
Propane is considered a fossil fuel and is in the class of liquefied petroleum gasses (LPGs) because it naturally occurs as a gas that can be converted to liquid. Propane is one of the most popular alternative fuels and vehicles that run on it produce less greenhouse gas emissions.
Biodiesel is created using a biomass like vegetable oil (such as soybean or canola), grease, or animal fat. It is also a renewable resource and produces no greenhouse gas emissions. When used to fuel vehicles, biodiesel is usually a blend of 80% petroleum diesel and 20% biodiesel, a mixture called B20. Vehicles that run on diesel fuel don’t need to be modified in order to run on B20.
Natural gas is a fossil fuel and is made up of mostly methane. In order to use it in vehicles, it can be compressed or liquefied (which requires colder temperatures than compression). Some vehicles run solely on natural gas while others, called dual-fuel or bi-fuel, can run on both gasoline or diesel and natural gas. Because it’s a fossil fuel, natural gas still produces greenhouse gas emissions, though not as much.
When nitrogen is liquefied, it produces a very low-temperature liquid (it boils at -321 degrees Fahrenheit). It can be used as a fuel in vehicles with special engines that heat the liquid in a heat exchanger and use the resulting gas for power. As a fuel, liquid nitrogen produces less greenhouse gas emissions.