This is a subject I`m not very educated on. I searched here before I posted but didn`t see what I was looking for. I checked my car`s air filters (my engine has two,one filter for the left cylinder bank and one for the right cylinder bank). Both filters still look showroom fresh. I bought my car with 34k on it and it now has 61k. I`m guessing as long as they look fine they`re ok? Who make the absolute best air filters? I`ve read AC Delcos are really good. What`s the general consensus?