Why Don't Cars Use Diesel Engines?
4 Answers
Noise and increased vehicle weight are the reasons why cars do not use diesel engines, as detailed below: Noise: Diesel engines produce significant noise during combustion, accompanied by noticeable body vibrations, which reduces driving and riding comfort. However, when used in larger vehicles, the vibration sensation is less pronounced, and the power output is much stronger than that of gasoline engines. Increased Vehicle Weight: Diesel engines are heavier. If installed in small-sized household cars, they would substantially increase the vehicle's weight and also lead to higher fuel consumption. The difference between diesel and gasoline engines lies in the higher compression ratio of diesel engines. The higher the compression ratio of an internal combustion engine, the greater its working efficiency. Diesel engines have a higher compression ratio because only air is compressed during the process, preventing premature detonation even at high compression ratios. Additionally, diesel engines rely on the compressed air's own temperature to instantly ignite the injected fuel, requiring the air to be compressed above the diesel's auto-ignition temperature. Diesel engines require more compression to increase temperature. The compression ratio directly affects the engine's efficiency and torque, so diesel engines with higher compression ratios can deliver greater torque, making them more suitable for heavy-duty trucks.
As a frequent driver, I feel diesel engines are less commonly used in cars mainly because they are too noisy. The roaring sound during startup and the strong vibrations inside the car make it feel like sitting on a massage chair, which is quite uncomfortable. Additionally, diesel emissions contain particulate matter and nitrogen oxides that easily pollute the air. With stricter environmental regulations now, automakers are shifting towards cleaner gasoline or hybrid options. However, diesel engines offer high torque and better fuel economy, making them suitable for long-distance travel or trucks. But for daily commuting, gasoline cars are quieter and smoother, with less maintenance hassle—like fewer filter changes or refueling stops—making the driving experience more pleasant.
From a technical perspective, diesel engines have higher compression ratios and better combustion efficiency, resulting in fuel savings, making them particularly suitable for high-speed or heavy-load scenarios. However, they suffer from prominent cold-start issues, difficulty igniting at low temperatures, and challenges starting in winter. Additionally, emission control is complex, requiring additional DPF systems to filter particulates, which increases costs and is prone to failure. In contrast, gasoline engines start easily, have simpler emission management, and require less maintenance, making them better suited for household vehicle needs. Therefore, many countries encourage the widespread adoption of gasoline vehicles through policies.
When it comes to environmental concerns, diesel engines have obvious shortcomings in automobiles, emitting high levels of nitrogen oxides, which exacerbate urban smog and health risks. Governments impose strict controls on this. I've seen data online showing that automakers are now shifting toward electrification or hybrid technologies, which are both energy-efficient and clean, such as Europe pushing new regulations to suppress diesel vehicles. Ordinary users opt for gasoline cars because they are quieter and won't disturb neighbors, making them more suitable for daily commuting and life overall.
