In your mind, diesel engines spew black smoke and make a lot of noise. They're either used in tractors or heavy trucks, right? But anyone who has been to Europe knows that many cars there run on diesel and drive so briskly! Why is there such a big difference in treatment?
What makes this “magic weapon” so magical?
The biggest advantage of a diesel engine is its thermal efficiency. To put it simply, it is very fuel-efficient. For the same displacement, a diesel engine uses only 60%-70% of the fuel of a gasoline engine, and even a gasoline hybrid can't match it. A pickup truck weighing over two tons can keep fuel consumption at the level of a B-class sedan, which is truly hard to imagine.
Another advantage of the diesel engine is its powerful low-end torque, which can reach peak torque in a low RPM range. Of course, torque also drops off quickly at high RPMs, but most people don't exceed 3,000 RPM in daily driving.
Emissions remain a point of contention.
Emissions are the biggest issue for which it has been criticized. As you know, Volkswagen's "Dieselgate" recently sparked a major public debate. In fact, thanks to high-pressure common rail technology and advanced exhaust gas treatment systems, diesel vehicles no longer spew black smoke. Moreover, they are widely used even in places like Europe, where emissions regulations are extremely strict, which is enough to prove their environmental friendliness.
But the car usage environment in China makes it impossible for it to achieve the best emission results. First, the quality of diesel fuel in China has always been inconsistent. Can you expect the exhaust after combustion to meet standards? Second, advanced diesel engine exhaust treatment technology currently still relies on automotive urea for processing. Many people probably don't even know what automotive urea is, let alone buy it and add it.
What stands in the way of its development?
Some say that diesel consumption in China is huge, and heavy trucks, ships, and industry all need it, so passenger cars should not get involved and compete for fuel. In fact, since there is market demand, sufficient diesel can definitely be provided, but the premise is that it can make money.
A very realistic factor is that diesel does not earn as much as gasoline. The profit from gasoline is much higher than diesel. So in the past two years, because diesel did not make much money, refineries were unwilling to produce it, which led to the phenomenon of trucks lining up to refuel with diesel. However, after a series of policy adjustments, diesel is no longer scarce and can fully meet supply.
The reason why passenger car diesel engines have not developed is that the government does not advocate them. Because diesel is still a fossil fuel energy source, it is not worth further promotion. Moreover, they believe that pure electric vehicles have broader development prospects and are more environmentally friendly (although even now, their environmental friendliness is still controversial).
Not only in China is it regarded as garbage
To be honest, the United States is also one of the countries where diesel engines are not taken seriously. After all, their fuel prices are cheaper, and they prefer large-displacement gasoline engines and do not like diesel engines. The popularity of diesel engines in Europe may just be a geographical advantage.
