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      08-10-2007, 12:18 PM   #22
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scalbert's Avatar

Drives: '13 S4, '15 Q7
Join Date: Feb 2007
Location: Woodstock, GA

iTrader: (8)

Originally Posted by Magna3 View Post
I doubt anyone can feel the difference on anything that makes 15hp or less. But, they have shown a gain of 1 to 4 hp on a dyno, .
A 5% gain is difficult to perceive for most. Anything less is just optimism. A filter alone will account for typically less than 1% if even that.

IMO, a clean stock filter will yield about the same gains as a maintenance type filter. So you can continually replace the factory filter, I do at every oil change, or maintain a filter and end with essentially the same power depending on when it was last changed or maintained.