Golf Car Catalog has a large selection of air filters for EZGO, Club Car, Yamaha, Harley, Columbia, and many other golf cart brands.
Your air filter should be changed at least yearly on any brand of golf cart. If the cart is used frequently, you should change the filter out several times per year. Filters are generally inexpensive and as always one dollar spent on preventative maintenance will save you hundreds of dollars in repair bills down the road.
As the name implies, your air filter, fuel filter, and oil filter, are used to filter out impurities which could greatly affect the performance of your golf cart. Your air filter is used to prevent dirt from infiltrating into the engine via your fresh air supply. A dirty or non-existent filter could quickly ruin your golf cart's engine. The cleaner the air is which is introduced into your golf cart engine, the longer it will last and the better it will perform.