Specs vs Application

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Jan 24, 2009
Northern Virginia
What are the dangers of selecting a filter based on thread size, media type, and can size and as opposed to just your vehicle or engine type?

In playing around with some of the look-up applications I can get a whole lot of different numbers that potentially would fit. I've also found multiple part numbers with essentially the same specs. Just makes me wonder how much difference there really could be between 2 similar filters.
Could always be running in Bypass or not have enough flow for your engine. Make sure the specs are identical except for the size of the media (filter size) and all should be ok.
Some filters don't have a bypass valve. If your car isn't designed to use that filter, you will tear the filter media (or worse) the first time you start your cold engine.

Some cars have significantly higher bypass pressure than others. For example, many VW engines use significantly higher bypass valve settings than most other vehicles. Make sure the bypass pressure setting is in a similar range.

Otherwise, it really doesn't matter.
The pressure relief rating is usually available. The flow rating is often tougher to find. Though I would have to assume that given similar sizes and media type that 2 similar filters would flow about the same.

I think it is pretty neat how you can get the data in the NAPA lookup window to export to excel. Just right click and export to excel. Sometimes the PSID rating will show as a date though.
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