Originally Posted By: edhackett
Originally Posted By: philipp10
"Oil filter efficiency does NOT improve with use."
Ahh do you have proof of that as I believe I have seen studies that say otherwise. I may have to do some digging.
Here's a start:
Quote:
The multi-pass test bench (ISO 4548) is a standardized test for the filtration of hydraulic fluids and engine filters for oil and fuels. By using particle counters upstream and downstream of the filter, the filter efficiency can be determined in a detailed way. The quotient of captured over total particles is listed as a function of the particle diameter. During the test, the changes of the fractional efficiency over the life time can be observed.
It is usually assumed that fractional efficiencies increase over time: particles deposited in the filter block the pores progressively which results in a decrease in permeability. Thus one tends to conclude that fewer particles will be able to pass through the filter and the efficiency rises over time.
However, measurements performed on filter media sometimes contradict this assumption, as can be seen in Fig. 1. Here, we observe decreasing efficiencies over a long period of time.
In fact, it decreases until the filter becomes complete clogged, at which point the efficiency sharply rises to 100%.
http://www.geodict.com/Publications/2013FiltechBeckerHahnLehmannWiegmann.pdf
Ed
Interesting Ed. It runs counter to information provided by the lead Fram engineer I spoke with some years ago at their labs. Basically suggested the 1 year 12k mi box recommendation was more/most about selling filters.
It also runs counter to what Jim Allen had long posted about air filter intervals and use. His thoughts are documented in the now classic (imo) bitog air filter thread started by member JOD, linked. His first post there is representative.
https://bobistheoilguy.com/forums/ubbthreads.php/topics/4348255/1