Differences between diesel and gas include fuel economy, emissions and cost. The two types of fuel are also rated differently.
One of the biggest differences between diesel and gas is that diesel gets far better fuel economy. On average, diesel is 33 percent more efficient, according to CarsDirect. Diesel engines also tend to have more torque, which boosts the fuel efficiency. Therefore, drivers can get quite a few more miles per gallon with diesel fuel than they can with gas.
Although diesel is more efficient than gas, it is not necessarily cleaner. Conventional diesel fuel can contain carcinogens and other chemicals that can harm the environment. However, many modern cars are designed with clean engines that filter out harmful substances, and many states are working to remove older models from the road. Still, drivers who are concerned about the environment should be sure to choose a car that has a clean diesel engine.
Diesel fuel is usually priced differently than gas. Often, diesel is more expensive, but sometimes it is cheaper than gas. However, even when the price is higher per gallon, driving diesel cars is usually cheaper due to the fact that diesel has better fuel economy.
Diesel fuel is rated based on its cetane number, which is different than the octane rating that gas fuel uses. The cetane number describes how fast the fuel burns and how easily it ignites. Diesel with a higher cetane number is more volatile.