First, from the working principle, both gasoline engines and diesel engines generate power by burning fuel, pushing the piston to move, and then driving the vehicle forward. However, there are significant differences in their ignition methods. The gasoline engine uses a spark plug to ignite the mixture, while the diesel engine relies on high-temperature and high-pressure air to make the diesel self-ignite.
Second, in terms of fuel supply, the gasoline engine usually mixes gasoline with air before entering the cylinder, while the diesel engine sprays the diesel into the cylinder at high pressure when the compression is close to the end. This different fuel supply method also leads to differences in their thermal efficiency and economy.
In terms of thermal efficiency and economy, diesel engines are usually better than gasoline engines. Due to the self-ignition characteristics of diesel, diesel engines can have a higher compression ratio, thereby improving thermal efficiency. In addition, the price of diesel is relatively low, which makes diesel engines more advantageous in fuel economy.
However, in terms of power and speed, gasoline engines often perform better. The gasoline engine has a higher speed and power output, which is suitable for occasions that require high power output, such as passenger cars. In contrast, diesel engines have lower speeds but greater torque, making them suitable for applications that require large torque, such as trucks.
In terms of environmental protection, diesel engines emit 30%-35% less carbon dioxide than gasoline engines on average, which to some extent reflects the environmental advantages of diesel engines. However, diesel engines may also produce pollutants such as nitrogen oxides and particulate matter, which require emission control through advanced technical means.
In addition, there are differences between gasoline engines and diesel engines in terms of noise and vibration. Gasoline engines usually run smoothly and make less noise, while diesel engines may produce greater noise and vibration.
Finally, from the perspective of application scenarios, gasoline engines are widely used in passenger cars, especially sedans; while diesel engines are more commonly used in trucks, construction machinery and other fields.
