If the filter is blue (Pro5R) or gold (ProGuard7), then it is oiled. If the filter media is grayish white (Pro Dry S), then it not oiled. With conical filters, look at the top. If it has the "aFe" or "Pro Guard 7" logo printed on the end, then it is an oiled type filter. If the filter has Pro Dry – S printed, it is an oil-free filter. Their may also be a part number on the filter. look for a small circle plug on the urethane part of the filter. There will be a part number located on it. Any numbers with 10-, 30-, 24- are Pro 5R, 11-, 31, 21- are Pro Dry S and any filter number beginning in 7 will be a Pro Guard 7 air filter.