Simple.......check the website for warranty info. Here's one for Purolator.
"Purolator Products Limited Warranty
Purolator filters are warranted to be free from manufacturer’s defects
in material, workmanship or design in accordance with the terms and
conditions described below.
New car warranties remain in effect when Purolator filters are used in
accordance to the engine manufacturer’s change intervals.
In the event of an engine failure directly caused by a defective Purolator
filter, which was properly installed and changed following the engine
manufacturer’s recommended service intervals and was in accord with
current Purolator catalog recommendations, Purolator warrants that it
will pay for the repair or, if necessary, replacement of an engine or other
parts damaged as a result of any defect in any of our filters.
Claims for engine repairs provided under this warranty must be
submitted within 30 days after discovery of damage. Purolator Technical
Services Department reserves the right to examine the engine and filter
to determine the amount of damage and whether it was caused by a
defective Purolator filter.
This warranty DOES NOT COVER any product that has been subjected
to misuse, neglect, negligence or accident, or that has been improperly
maintained, operated or installed. The warranty DOES NOT APPLY to
any damage to the product that is the result of rust or corrosion.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES
EXPRESSED OR IMPLIED, INCLUDING THE IMPLIED WARRANTY
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE WHICH ARE EXPRESSLY EXCLUDED. PUROLATOR
SHALL NOT BE LIABLE FOR CONSEQUENTIAL OR INCIDENTAL
DAMAGES RESULTING FROM OR CAUSED BY THE USE,
OPERATION, FAILURE OR DEFECT OF ANY PUROLATOR FILTER.
This warranty gives you specific legal rights. You many also have other
rights which vary from state to state."
Pretty explicit regarding engine repair or replacement. Sure, you need to present proof, but engine replacement is pretty pricy, if I recall right. They have the right to verify what happened.
I recommend going to the CalSci site,
http://motorcycleinfo.calsci.com/Filters.html#OilFilters Read up and do your own homework.
Warranties are a double edged sword. Either your product is so poor you need one (and soon go out of business) or it's so good you don't. It ultimately boils down to reputation.
Make your most educated choice and live with the outcome.
Oil filter discussions always go this way and usually result in unnecessary anxiety.
Don't Worry, Be Smart (and Happy)...that's what riding is all about.
S-Ten