Why Do Japanese Cars Not Have Particulate Filters?
2 Answers
Most Japanese cars do not have particulate filters because they predominantly use naturally aspirated engines, which produce relatively low levels of exhaust emissions. Therefore, installing particulate filters to improve emission quality is unnecessary. Car owners should note that if their vehicle is equipped with a particulate filter, it is advisable to use low-ash engine oil. Low-ash oil generates fewer particulates during operation, thereby reducing the risk of clogging the particulate filter and better protecting both the engine and the filter's lifespan. The working principle of a particulate filter involves coating the diesel particulate filter with metals such as platinum, rhodium, and palladium. The black smoke containing carbon particles emitted by diesel engines enters the exhaust particulate trap through a dedicated pipeline. The densely arranged bag filters inside capture the carbon particles on a filter made of metal fiber felt. When the accumulated particles reach a certain level, the burner at the end automatically ignites, burning off the captured carbon particles and converting them into harmless carbon dioxide before being released.
Japanese cars are not completely devoid of particulate filters, but they use them relatively less. This is because Japanese brands place more emphasis on reducing particulate emissions at the source, such as by optimizing engine combustion efficiency. They excel at improving direct fuel injection technology, ensuring thorough gasoline combustion, which naturally reduces the production of soot particles. Hybrid systems like those from Toyota can also significantly decrease particulate generation, eliminating the need for additional components like filters. In fact, installing particulate filters would increase costs, complicate maintenance, and require owners to drive at high speeds to prevent clogging. Japanese cars can meet emission regulations through technological optimization, so they naturally prefer more hassle-free solutions.
