My question is a filter sock required for the dunes. My son says if I don't want fine sand in my Teryx I should get a filter sock. Is he right or will the stock filter keep the fine silt out. If I need one, what brand is best and where can I get it. Thanks for the answers. Getting ready to go to Pismo Beach, Ca for vacation and don't want to buy a new engine at 12.8 hours. Sounds like I made it further than some with just 12 hours.