My Buick can take a standard short filter, or a longer double length filter. I always use the longer version.
For example, the Baldwin standard/short version is B43-S. The longer version is B35-S. Every manufacturer makes a short and long version. The short version is what comes up if you search for an oil filter for 97 Buick Park Ave. I always find long versions of each brand by cross referencing to Baldwin B35-S or Wix 51036.
Take a look at the specs below, which I got from each brand's website.
Premium Guard (under their own brand name) gives us a choice between excellent/efficient filtration or having a silicon valve & gasket. You can't have both from PG brand name.
Premium Guard (short) PG111 website says 15~25 microns, black nitrile valve & gasket.
Premium Guard (short) PG111EX says 42~60 microns, pink silicon valve & gasket.
Premium Guard (long) PG4011 says 15~25 microns, black nitrile valve & gasket.
Premium Guard (long) PG4011EX does not exist.
Oreilly Microgard Select (long) MSL51036 says 99% @ 25 microns, has pink silicon valve & gasket.
Napa Gold (long) 1036 says it's 99% @ 30 microns, has pink silicon valve & gasket.
Autozone STP XL (long) 3980XL says it's 99% @ 20 microns, has pink silicon valve & gasket.
Advance Autoparts Carquest Premium (long) 85036 says 99% @ 20 microns, has pink silicon valve & gasket.
The claimed filtration specs are all over the place. It makes me wonder how accurate claimed/stated specs are. I doubt that Premium Guard is making several different filters for my car, each for a different auto store, and with different filtration efficiencies for different auto stores.
My best guess is that all the Premium filters made by PG sold under autostore housebrand names probably all really filter at around 25-30 microns, which is excellent.
I think when autostores say 20 microns (or less) they're trying to mislead us with excessive optimism. When they say 25 they're being honest and realistic. When they say 30 they're being honest and conservative. IMO
99%@30 microns is excellent, IMO. It's a lot finer than Baldwin's 99%@40 microns, or whatever Wix is (which is larger than 40).
The AC Delco Ultraguard Gold UPF47R claims 98% @ 30 microns. So I think 98% or 99% @ 30 microns sets the bar for excellence. I think 40 is better than average. I think average is around 45-47 IMO. So I'm happy with anything 40 or less. Overjoyed with 30 or 25.