Does Bypass Setting Matter?

[carock]

I do not understand why a the ratings for the bypass valve make any difference to the engine.For instance, if one filter has the bypass set from 11-14 psi and the other from 8-11 psi doesn't the engine receive the same oil flow all the time? I thought the bypass setting was determined by the filter manufacturer to protect the filter element.

 

[Gary Allan]

You've got it. Well, let me qualify that. The bypass may indeed be there to protect the engine from oil starvation. You could surely exceed the oil pump's releif setting and reduce flow substantially if there was no bypass valve/mechanism. BUT THE ACTUAL BYPASS SETTING (inside a certain range) is determined by the strength of the media.

Now VW/AUDI have 30lb bypass settings. They not only factor this into their total oil scheme ..but it's one h-ell of a reinforced media.

 

[unDummy]

Yep, its to protect the element. But, a high quality media might not need as much protection. Or, some engines might be too picky if the oil PSI drops too much through a restrictive media.
Other engines might have overengineered oil systems and might prefer all the oil filtered all the time(certain german engines, diesels, and those engines with fancy features like variable cam phasing, turbos, or oil cooling jets....).

Oil flow, pressure drop, and volume% of oil actually filtered are some variables that are balanced.

 

[labman]

I sometimes wonder how much real data the engineers have when they specify the bypass pressure.