Just like I mentioned above. Why would one xyz brand/model filter look wavy off of engine A, but the same zyz brand/model filter have pretty much straight pleats off of engine B?
You "think" it might be worse on Fram filters, but you have zero data base to prove it. It's just a subjective conclusion based on seeing some that look pretty bad. There have also been some non wire-back Ultra with pretty straight pleats. Then all of a sudden only Frams have wavy pleats, and the ones with barely wavy pleats don't qualify for the centerfold.
We do see it random across many brands of filters. You seem to think it's only a Fram thing. Lot of M+H/Purolator filters have also shown wavy pleats ... even Motorcrarfs. It's not. I said 12 years ago that wavy pleats are just a visual aspect and don't hurt anything.
Here's a PureOne PL14459 off an Altima V6 I cut open in 2010. Look familiar?
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Here's a Motorcraft FL822 off that same Altima V6 I cut open in 2009. And both of those were 5000 mile runs Yes, it always can happen if the filter is not 100% fully synthetic media.
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