Originally Posted by GIdriver
That's my point! Earlier E9x M3's had a more restrictive charcoal lined air filter. More recent models have the same euro edition air filters, which are less restrictive. Lets be honest here: There are NO MAJOR GAINS in horsepower by changing the air filter on latter models. I like how your filter is built (excellent build quality) and the intake sound that comes with it, though. I will be buying it again.
Our filters were originally designed to replace the early filter and we saw gains upwards of 8-10hp. We later adapted it for the new style airbox. While gains were not as impressive against the euro filter, it is still worthwhile to run to get every bit of power out of your ///M