Makaveli wrote:So in another words there is a 50/50 chance that aftermarket filter is good and to avoid the "guesswork" just buy genuine?
That's sound advice.
Two separate incidents changed my views on filters.
About 18 years ago we put an aftermarket filter on my 2E rally engine following a very expensive rebuild. The thing seized in the middle of it's 2nd competitive stage.
Thinking I must have done something wrong I took the car complete to a renowned expert in these engines for him to dismantle. He couldn't find a thing wrong other than the aftermarket filter.
He recalled that AVIS rental cars had experienced a string of engine failures with 2E powered Corollas & Starlets when they installed cheap non OE filters.
He rebuilt the engine exactly as it was and installed a factory filter and that car went on to complete two full seasons of rallying including two 4 day Rally NZ's.
About the same time I had bought my wife a late model low mileage Mazda V6. Before she went away on a long trip I changed the oil & filter and almost immediately we noticed the top end getting noisy.
On calling my friendly Mazda service manager, before I even had a chance to tell him what I'd done, he said "you've changed the oil haven't you, and you didn't use a genuine filter?" He was right and after changing back the problem all but went away.
So in my view, at $40, a genuine filter might seem expensive in comparison to cheaper aftermarket items but in reality they're good insurance.