Originally Posted by spearfish25

Remember that finer filters may result in lower flow through the filter or require increased pressure to maintain the same flow.

I don't say this from real-world numbers on a car, but in relation to other filter applications. For example, your home airconditioner has those exchangeable filters that slide in. If you use a regular, cheap filter that doesn't filter as well...your airconditioner blows more air and cools faster (at the expense of some more dust in the air). Exchange that filter for one of the allergy fighting, super fine filters and you'll have pristine clean air but the a/c takes much longer to cool your home since the airflow is decreased by the increased filter resistance.

My concern with the finer oil filters is that they follow this trend...a fine filter also impedes your oil circulation. Instead, I use a magnetic oil plug as well as a filtermagnet directly on the oil filter.