Yesterday I was reminded of the serious potential drawbacks of using a filter that is too big. I have a case and a half of AC Delco Ultraguard Gold filters (PH8A size, 3/4-16 thread) that I'm just itching to use up, my Ford truck takes them but I only use one a year or two at the rate I drive the thing.
Figured I could erase the stash a little quicker and use the filters on my Pacifica, which normally takes a PH16, also 3/4-16 thread, comparable bypass valve specs and gasket diameter. Both filters are nearly identical in girth, however the PH8A size is about 80% longer.
When installed on the car, the filter came down too far (it's mounted straight down) to be protected by the various plastic shrouds / subframe on all sides, but after inspecting it closely, I decided it would take a very (un)lucky strike from road debris at just the right angle and placement to hit the filter in some way. I've only had the filter on for a week, and boy was I mistaken! It wasn't even my wife driving (who finds a way to hit undercar obstacles like tall curbs routinely, usuallly just under the bumper scrapes and such) but me simply pulling into a parking space at the dollar store! While inching up to the curb, I felt an awful-sounding metallic scrape and sure as [censored], the angle on the cement curb hit the filter just right so as to crush the very edge of it. The filter didn't leak and all was well after replacing it-- using the stock PH16 from now on, and not even taking a chance in the future! In retrospect it was a foolish idea, as the PH16 is sufficiently large to begin with for an engine of the size, and using a $2 filter up is not worth a potential catastrophe.
Figured I could erase the stash a little quicker and use the filters on my Pacifica, which normally takes a PH16, also 3/4-16 thread, comparable bypass valve specs and gasket diameter. Both filters are nearly identical in girth, however the PH8A size is about 80% longer.
When installed on the car, the filter came down too far (it's mounted straight down) to be protected by the various plastic shrouds / subframe on all sides, but after inspecting it closely, I decided it would take a very (un)lucky strike from road debris at just the right angle and placement to hit the filter in some way. I've only had the filter on for a week, and boy was I mistaken! It wasn't even my wife driving (who finds a way to hit undercar obstacles like tall curbs routinely, usuallly just under the bumper scrapes and such) but me simply pulling into a parking space at the dollar store! While inching up to the curb, I felt an awful-sounding metallic scrape and sure as [censored], the angle on the cement curb hit the filter just right so as to crush the very edge of it. The filter didn't leak and all was well after replacing it-- using the stock PH16 from now on, and not even taking a chance in the future! In retrospect it was a foolish idea, as the PH16 is sufficiently large to begin with for an engine of the size, and using a $2 filter up is not worth a potential catastrophe.
