Originally Posted By: dparm
http://www.dieselplace.com/forum/showthread.php?t=117009
The only legit/independent test I've ever seen. Draw your own conclusions, but I decided to keep my OEM paper one on.
Ahhhh the Spicer test! Good for sure but now dated (2004). The general trends are accurate, though most of the products have changed now.
Overall, my recommendation would be for a dry element but whatever your choice, compare the specs... which requires a little knowledge. You may or may not see the efficiency specs listed, or what specs you do see are highly filtered (pun intended) by marketing people.
What you want are tests done under ISO 5011:2000. Next, find out whether the test was done with fine or coarse test dust. You cannot compare tests on coarse and fine, as the fine dust challenges the filter much more. Real Example: A test that delivers 98 percent efficiency on coarse dust might only be 92 percent on fine dust and vice versa (you can see something similar in the Spicer test). If you find a filter that does 98-99 percent on fine dust, you have a good filter from the efficiency standpoint.
When comparing filters, make sure you are comparing the same tests. I have seen biased (or ignorant) comparisons that cite the coarse spec for the favored filter and the fine spec for the non-favored. Virtually any filter better than mom's old panty hose will do 98+ on coarse dust. Any filter worth a modecum of consideration should do 99+ on coarse.
All the preceding presupposes efficiency is the main goal. If airflow/performance is, then lower efficiency is often the price. In a few instances, you can have both. Some CAIs have oversized elements that offer an increase in airflow but because the media is so much larger, the media can be efficient as well. The only one I can point you to that I know 100 percent in all areas this is the case, is the AEM Brute Force with the Dryflow element. Very efficient media... 99+% on fines.