1. Using low-cost filter paper to produce filters, because of its large pore size filter paper, poor uniformity, low filtration efficiency, the engine will not effectively filter harmful impurities, resulting in early engine wear.
2. Use low-quality adhesive, and dosage is very few, neither oil resistant, nor strong adhesive, causing a short circuit filter bonding; or use the staple cartridge connecting seams, unable to seal and short circuit, so a lot of harmful impurities into the engine, reduce engine life.
3. Using ordinary rubber instead of oil resistant rubber parts, in the process of using or filter internal short circuit formed by the internal seal seal failure cause engine early wear and cutting life or expansion deformation of external the seals, causing oil filter outside sealing ring out, a short time, a large number of drainage, make the engine burn watts, holding shaft, suffered severe damage.
4. Air filter shell parts welding with alternative spot welding seam welding, no guarantee that the sealing, form a short circuit.
5. The oil filter center tube material is thin on behalf of thick, strong enough, in the course of suction deflated due to the central tube, plug the oil filter damaged, resulting in lack of engine lubrication; poor or seams at the reliability of the course at the seams pull open, resulting in a large number of oil leak in a short time, resulting in bush-burning, axle.
6. Filter plate, center pipe, casing and other metal parts, without antirust processing, cause metal corrosion impurities, makes the filter become a pollution source. What’s more, use the cement instead of adhesive, its harm is greater.

Therefore, the cost of using inferior filter is very big, we suggest that users must be careful when replacing filters.