What are the Differences Between Gasoline and Diesel Engine?
When choosing a new tool, there are several factors to consider. You have to decide on a model you want, whether it’s a sedan, SUV, etc. Next, you need to choose what kind of available features you want. You should also consider whether you want a petrol or diesel engine. However, then you may be wondering the real difference between petrol and diesel. This helpful guide will go over the major differences between these two engines so you can decide which one is right for you.
Invention of Gasoline and Diesel Engine
The difference between diesel and gasoline engines begins with their invention. In 1876, Nikolaus August Otto invented the gasoline engine. This four-stroke internal combustion engine was not particularly efficient. Only about 10% of the fuel was actually used to power the vehicle. The rest of the fuel just produced heat. However, this gasoline engine presented the basic blueprint for modern car engines.
In 1878, Rudolf Diesel was studying engineering at Polytechnic High School when he learned about the inefficiency of gasoline engines. He believed there had to be a more effective solution and set out to explore it. In 1892, he invented and patented what was then called the combustion engine. Today we know it as a diesel engine.
Gasoline vs. Diesel: Key Differences
Basically, gasoline and diesel engines have similar processes. Both engines use internal combustion and a series of rapid ignitions within the engine to propel a vehicle forward by converting fuel into mechanical energy. The difference is how these ignitions occur.
In gasoline engines, the fuel mixes with the air compressed by the pistons. Spark plugs ignite this mixture to move the vehicle. In diesel engines, the air is compressed first. This makes the air hot. The fuel then ignites when it hits hot air.
Gasoline and diesel engines inject fuel in different ways. In a gasoline engine, fuel injection can take place in two ways: port injection system or carburetor. The port injection system injects air into the fuel just before the intake stroke. In contrast, a carburetor mixes fuel and air before sending them into the cylinder for compression.
In a diesel engine, fuel is injected directly into the cylinder. Since this process is such an important part of how diesel engines work, diesel injectors can become a complex part of the process. In order to disperse the fine fuel mist necessary for the operation of the process, the injectors must be able to withstand high temperatures and large amounts of pressure. To date, engineers are working to make this system more efficient.
Examples of engine improvements include engine control modules and glow plugs. Engine control modules use multiple sensors to accurately time injection, and a glow plug is a hot wire that can quickly raise the air temperature on a cold engine to help it run more efficiently.
As you research your new vehicle options, you may see a lot of talk about horsepower and torque. Horsepower is a measure of power and torque is a measure of the twisting force on the drivetrain in the engine.
If your vehicle has a lot of horsepower but less torque, it will be slow to move. Torque is what makes cars move. Diesel engines tend to have higher torque but less horsepower. This is why sports cars often have petrol engines, and large trucks often have diesel engines. Sports cars need the extra horsepower offered by gasoline, and large trucks need this extra torque from the diesel engine to move heavy loads.
In addition to the power differences, another difference between petrol and diesel engines is efficiency. Diesel engines tend to have higher fuel economy figures compared to gasoline engines. These higher efficiency numbers are mainly due to the way the engines work. A gasoline engine must ensure that it never reaches autoignition temperature during the compression stroke as this could potentially ruin the engine. As a result, a gasoline engine has to maintain a low compression ratio.
Since there is no fuel in the mixture during the intake stroke of the diesel engine, it can compress the air more and have a higher compression ratio. A higher compression ratio equals better fuel efficiency.
Gasoline Fuel and Diesel Fuel
Gasoline and diesel engines require different types of fuel because they work differently. While both gasoline and diesel start as crude oil extracted from the ground, the refining process breaks them down into various types of fuels. Diesel fuel is thicker than gasoline, which means it evaporates more slowly. Diesel fuel also has greater energy density.
These features are another reason why diesel engines tend to have better fuel economy than gasoline engines. While diesel fuel typically costs more than gasoline, most diesel engines require less fuel to perform the same amount of work as a gasoline engine. In addition, diesel engine owners have a new refueling option available to them.
Biodiesel: Biodiesel fuel is made from non-petroleum sources such as vegetable oil. Converting a diesel engine to run on biodiesel requires some modifications, especially if you have an older engine. However, as efficiency and sustainability become more popular, biodiesel may be the next common alternative fuel.