Originally Posted By: Drew99GT
Just for clarification, the Proguard IS NOT the same filter as the Pro 5R. The Proguard is a 7 layer oiled filter with 5 layers of gauze and 2 layers of synthetic media. It's one of the best reusable filters made and is 99.7% efficient. Likely better than most disposable filters.
The Proguard family groups the oiled filters provided by AFE. It includes both the pro 5R and the Proguard 7. The Proguard 7 is a Pro 5R to which 2 additional synthetic layers have been added.
The best filtration of the two is provided by the Proguard7, clearly. The Proguard 7 has been tested in comparative ISO 5011 tests in the past 7 years (we could not find equivalent tests for the Pro 5R, but they should be worse than the Proguard 7) and typically shown to do significantly better than the K&N, a little better than the Airaid, and worse than the AEM.
The 99.7% number is provided by AFE, and is higher than what the tests have shown. It is also measuring *cumulative* efficiency, meaning that the initial efficiency of the filter is significantly lower, since filters filter better with a dust cake. Why is this important? Because reusable filters get washed often, which means that they are typically very clean, which means that actual filtration efficiency is significantly worse than measured cumulative efficiency - even when the cumulative efficiency number is a true one
All reusable filters appear to do, in general, worse than the disposable OEM filters in filtration performance. Among the reusable filters, so far we have found the AEM and the AFE Proguard 7 to get closest to the OEM filter performance, with the edge to the AEM. But this could change as we go through more test results.
Hope this helps -