Oil bath type air filter has a long history, this kind of air filter is directly installed on the air intake tube of the engine with small volume and convenient layout, there is no need of big layout space. It has long working life and can maintained and used repeatedly, but this kind of air filter has low efficiency and the efficiency will be changed according to the working situation, if in rated condition, the efficiency high, if in partial load the efficiency low, while this auto engine is working under part of conformity, so the actual filtration efficiency of this kind of air filter is relatively low. What’s more, when maintaining this kind of air filter, it needs to use gasoline to clean and cause the waste of oil material. It needs more time to maintain.

Papery type dry air filter is widely used in automobile with high efficiency, which will not be influenced by the engine load change.  It is easy to maintain and there is no need to use gasoline to clean and will not be restricted to objective condition. The filtration efficiency has natural growth effect, the efficiency cannot decrease with time going, but it can grow a little. The layout of the filter can be upright installed and horizontal type installed. It can use direction light to control the highest allowed value of the air intake resistance to confirm the promptness of maintenance, to confirm the engine function and prolong the lifetime of the engine.