Air Filter Study, Flow Rate and Filtration Options

[pvollma]

I found the link to this study on a Lincoln Town Car forum:

Air Filter Comparison Study

While it was done using air filters for a GM Truck, the conclusions are interesting:

1. choosing a filter type or style for ‘more flow’ for either performance or fuel mileage is useless, as they all flow about the same

2. there is a wide variance in the ability to filter contaminants; the best was an unoiled synthetic fiber passing less than 1% of the contaminants introduced, while the worst was an oiled foam allowing 40% to pass. To bring in some 914 relevance, the K&N was second-worst, passing 35%.

I make no claim that this applies directly to our 914s, but I found it interesting since I've always used K&N filters on my performance cars.