WHY DO TRUCKS USE DIESEL? When you’re at the gas pump, you’ve likely realized there is both gasoline and diesel on offer. You probably even know that semi-trucks use diesel. But why do they use diesel and how does it help semi-trucks run better?Why do trucks use diesel? Trucks use diesel and not gasoline because this leads to more fuel efficiency, which cuts down on overall costs. Diesel engines require less maintenance and are more reliable. Diesel is also cleaner than it used to be and diesel engines are designed in a way to filter out unwanted contaminants. Semi-truck drivers can use Diesel One if they are driving in very cold conditions or Diesel Two if they are in more temperate areas. Most diesel engines can also run on up to 20 percent biodiesel, which is made from recycled vegetable oil or used cooking oil.Types of DieselThere are actually two types of diesel fuels, named Diesel One and Diesel Two. While semi-trucks can technically use either fuel source, Diesel Two is the more common source.Semi-trucks that frequently travel in colder temperatures, will use Diesel One as it has a lower viscosity. Diesel One won’t become thick with extreme cold, so it is safer to use.You may also see a mixture of Diesel One and Diesel Two at fueling stations. This blend works well if you travel through a wide range of road and weather conditions.One final option for diesel is biodiesel. This is made from a combination of vegetable oil, used cooking oil, or animal fats. Due to its construction, most semi-trucks can use a blend of biodiesel, usually in the 20 percent range.How is a diesel engine different than a gasoline engine?The structure of a diesel engine is different from that of a gasoline engine. You can’t mix up the two fuel sources as this will cause either engine to stop working.A gasoline engine starts with fuel that is then mixed with air. This mixture is compressed by pistons and a spark plug unites it, which then powers the engine.A diesel engine starts with compressed air first. Then, fuel is injected. The compressed air will naturally heat up, which then ignites the fuel.The biggest difference between a diesel engine and a gasoline engine is that there are no spark plugs.Reasons why diesel engine is used for trucksCostThe cost of gasoline and diesel are always changing and currently, diesel is slightly more expensive. However, this was not always the case and most often, diesel is the cheaper alternative.Even if the price at the pump shows that diesel is more expensive than gasoline, it still has a better fuel mileage. Filling up with a tank of diesel means drivers can travel longer distances before having to stop for gas, which means it is cheaper overall.While gasoline has the current advantage over diesel, it is only slightly. And, as the current market shows, gas prices are very volatile, so a reversal in price is expected in the near future.EfficiencyThe more efficient your fuel source is, the more weight you can carry. A diesel engine is able to produce 147,000 BTUs of energy while in contrast, while gasoline is only able to produce 125,000 BTUs.Semi-trucks carry very heavy loads and will try to maximize this weight to cut down on overall costs. The more energy an engine can create, the easier transportation becomes.While semi-trucks would still be able to transport large loads of gasoline, this would take longer and more trips. The extra energy from a diesel engine is imperative to the success and profit margin of the trucking industry.Less maintenanceWhile semi-trucks still need periodic maintenance the length of time between these checkups is doubled with the use of diesel over gasoline. An engine that runs on gasoline needs a checkup every 6,000 to 10,000 hours of usage, while a diesel engine can last between 15,000 and 30,000 hours.Higher torqueNo matter the terrain, semi-trucks need more power and thus more torque to navigate their routes. This is even more true if they drive in windy, hilly, or mountainous areas.Diesel produces more torque in an engine than gasoline does, which is why it powers a semi-truck engine.What are the benefits of diesel truck engines?Diesel engines have a higher compression ratio, which allows the fuel to ignite on its own, without the use of spark plugs. Having one less piece of the engine increases its lifespan.Another benefit is that diesel engines work at a more consistent temperature. This creates a better fuel economy, which decreases the cost of fuel and leads to fewer stops from the driver.Why are petrol engines not used in trucks?The bottom line is that diesel engines are better for a trucking company than gasoline or petrol engines. Trucking companies, just like any other business, need to find ways to cuts costs and turn a profit.There used to be a perception that diesel engines were bad for the environment but the opposite is actually true. This is largely thanks to emissions standards that have come in at the government level.Overall, diesel contains more carbon than gasoline does, and releasing carbon dioxide into the atmosphere can negatively impact the earth. However, diesel engines are more efficient than gasoline engines.So, because of their efficiency, less carbon is actually released with a diesel engine than with a gasoline engine.If you have an older semi-truck, your engine will not be as clean as a gasoline engine. However, thanks to more stringent standards, new diesel engines are not the big polluters they used to be, and so have a better place on the road.ConclusionSemi-trucks use diesel because it is cheaper and more efficient. Diesel does not need a spark plug to combust, as the engine is created differently. While diesel still has a bad reputation for contributing to carbon dioxide levels, there has been a large push recently to make diesel engines cleaner and better for the environment.