What are the differences between gasoline engines and diesel engines?
2 Answers
Here are the specific differences between diesel engines and gasoline engines: 1. Fuel supply and ignition method: In diesel engines, fuel mixing and combustion occur inside the cylinder. High-pressure diesel is directly injected into the combustion chamber by the fuel injector, mixes with air to form atomized gas, and then ignites after compression. Therefore, in terms of structure, gasoline engines have an additional complete ignition system compared to diesel engines. In gasoline engines, gasoline from the fuel pump mixes with air from the air filter in the carburetor to form a combustible mixture, which enters the cylinder combustion chamber through the intake manifold and is ignited by an electric spark. 2. Fuel: Diesel engines use diesel fuel. The cetane number is an indicator of the self-ignition performance (combustibility) of diesel fuel, while the distillation range represents its volatility, and viscosity measures fuel fluidity. Gasoline engines use gasoline. Knocking is an abnormal self-ignition phenomenon that may occur during gasoline engine combustion as the compression ratio and cylinder gas temperature increase. A higher octane number indicates stronger anti-knock capability, allowing for higher compression ratios. Anti-knock additives, commonly lead compounds, are often added, making gasoline more lead-containing. 3. Corrosion resistance: Diesel engine main bearings and connecting rod bearings use high-performance materials like lead bronze or lead alloys, which have relatively poor corrosion resistance. Gasoline engine main bearings and connecting rod bearings can use softer materials with better corrosion resistance, such as Babbitt metal.
Having driven for decades, I'm quite familiar with these two engine types. Gasoline engines rely on spark plugs to ignite the air-fuel mixture, offering responsive acceleration, quick city driving pickup, and flexible stop-start operation – ideal for daily commutes. However, they consume more fuel, especially in traffic jams. Diesel engines differ; they compress air to high temperatures for fuel ignition without spark plugs, achieving higher efficiency. The fuel savings are particularly noticeable on long trips – my diesel SUV can travel an extra hundred kilometers per tank. But they start slower with louder noise, especially during winter warm-ups when they rumble noticeably. Maintenance-wise, diesel engines are durable but require more frequent filter servicing at slightly higher costs, while gasoline engines are easier to repair. Overall, gasoline suits households prioritizing quiet comfort, whereas diesel offers better value for commercial use or frequent cargo-hauling trips.
