not too long ago i purchased an 05 sport edition and i'm glad i found this site. i was looking for some free 'mods' for my engine and found this thread. i will be removing my hydrocarbon filter tomorrow. i don't think it will give noticeable power but i figure why not...i may gain a horsepower or two...

anyways, i see a lot of people on here wondering and claiming that you can get better gas mileage from removing it. i see confusion all the time about intake products and mods that will supposedly give you better gas mileage.

we can all agree that the hydrocarbon filter is restrictive to some degree (maybe insignificant but maybe not). we can all agree that because of the restriction there is a pressure drop across the filter. any pressure drops in the intake system means less air molecules into the combustion chamber during the intake stroke which means less power. so most people figure that by reducing the pressure drop in an intake (such as by removing the hydrocarbon filter) that you would in turn gain fuel economy (maybe an insignificant amount or maybe significant).

this idea is completely wrong. remember, the engine power and the amount of fuel that is combusted is regulated by the throttle / butterfly valve. the throttle intentionally creates a pressure drop. so any reduction in pressure drop through the intake system caused by removing the hydrocarbon filter would mean that your right foot would simply be slightly less on the gas pedal for any particular speed. the free-er flowing the intake, the more closed the throttle will be. there is no impact to gas mileage.