Major maintenance contents:
　　Major maintenance refers to the routine maintenance of oil replacement, oil filter element, air filter element and gasoline filter element within the time or mileage specified by the manufacturer.
　　Big maintenance interval:
　　Big maintenance is based on the existence of small maintenance, generally these two kinds of maintenance alternately. The intervals are different due to the differences of automobile brands. Please refer to the manufacturer's recommendation for details.
　　This paper is sorted out by dongguan oneness filtration technology co., LTD