Hello ShootingStar,
You are just bringing up a good point about the filter manufacturers different point of views.
Some of the manufacturers are aiming to have what we would call "Will Fit" filters while others are more into the "Exact Specs".
The "Will-Fit" filter is a compromise in specifications where the manufacturers can decided to have one filter fitting 3 to 4 different applications. It's only requirements is that it will fit the application, the by-pass valve setting would ideally be set for the lowest pressure required by the different applications. There are also some manufacturers that are using the same filtration media across their automotive filters.
Then there are the "Exact Specs" manufacturers which will base their design on what is required by the Original Equipment Manufacturer. They will start their research buy buying 48 to 72 filters of the same part numbers from a local OE Dealer for the application their are looking to make filters for.
Their will get those filters in their laboratory and extract the performance of that filter. They will usually repeat the tests a minimum of at least 3 times for all the test and they will average the results obtained. Some of the test conducted will be to find out the efficiency, capacity, burst pressure, pulsation testing.
They will also tear appart some new filter to get samples of the filtration media used so they can determine it's property. Flow testing, tear resistance, Bubble Test are only a few of the test they will run on the filtration media to find out what type of media they will need minimally to meet the OE.
They also will measure all the parts of that filter (metal can, base plate, centre tube, gasket & end caps).
All those testing results will dictate what they will have to do to meet the OE specifications.
Then it is their choices to meet or exceed OE specifications.
Sometimes, the market will dictate to the manufacturer the road to take.
Example, some large surface retailer (K-Mart, Wallmart, Canadian Tire, etc) wants to offer filters for cars for wants the offering to be the least numbers required to cover the most cars (or have the least part numbers covering the most applications).
This is not going to point to any specific brand but some manufacturer are really bad for it.
Another thing to prevent miss-applications of filters be sure to lookup the application in the filter's manufacturer application guide. If you want to know why?, read the warranty statement in the back of that guide! here is an small part of it:
So&So Filter Manufacturer warranty their filters to be free of defects in material and workmanship and will cover the cost of damages to an engine if the filter should be defective as long as the filter as been used for the application it was designed for.
The reason their all use a very similar statement is very simple. There are alot of filters today that have the same physical dimensions & thread but are totally different on the inside and the only way to make sure you are using the correct filter for your application is to look it up in the application guide provided by the filter manufacturer.
Best regards from Montreal, Canada
Rob.
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Originally posted by ShootingStar:
quote:
Originally posted by bill99gxe:
A bit surprising that the 1004 is spec'd for Hondas, yet the pressure is 11 to 14psi instead of around 20psi.....
Is 20psi number the accepted, gospel truth, bypass valve setting of a Honda OEM filter? I've wondered for a long time what it REALLY is since all these filter makers use a single number and apply it to many brands cars. In other words, they're all more or less universal within the given paramaters of thread size, gasket size, etc.
