Alright, lets be honest....most people replace their ugly plastic fuel and oil filter caps with these just because they look a heck of a lot better. But, to help the argument, these really do have functional benefits compared to the stock caps. No, really! First, these caps have the same footprints as the OEM Ford caps, compared to some aftermarket filters and caps which allow oil to bypass the filter, causing unfiltered oil to enter the system, but not with the Bean Machine cap! Secondly, these caps are tapped with 1/8" NPT for use with an oil pressure gauge , oil temperature sending unit, or fuel pressure gauge to allow for a quick and simple way to hook up auxiliary gauges to monitor your vital powertrain parameters. Oh yeah, did we mention these look awesome?!