INCORRECT, because unlike religion, politics, and likely sex (broad topic), air filtration is empirical -- measurable data can be collected and compared without anecdotal bias nor experimental confounds.abscate wrote:Add "air filter" to sex, religion, politics, and oil change intervals.....
Oil change intervals can also be empirically studied (versus speculated) as a science; the discipline is called tribology, and any reputable lube supplier will either have one or more on staff (large company) or contract with companies who do who provide testing. Newer cars are increasingly equipped with sensors to monitor oil condition and will alert before the standard mile change interval if used in harsh, dirty conditions, and after if used in clean, highway ones. Barring that, manufacturers provide recommended oil grades, providers, and service intervals based on their own tribology testing. Owners wanting to make informed choices about using other oils can consult their respective MSDSs, request tribology results from the manufacturer, or send in a sample of their oil to a tribologist for testing.
As instarx notes above, those who laud K&N are most often exhibiting Conformation Bias (as opposed to Buyer's Remorse) and or Cognitive Dissonance in that
"I just paid $$ and spent ##:## time making this change,
which if it doesn't make my car better means I've wasted my time and money,
but I'm neither inefficient nor wasteful,
so it must have been a good decision,
and the product has to be working as advertized,
(even if I can not measurably prove it
using the exact same conditions
where the operator's actions can not be influenced
by knowing which is being tested,
nor other variables introduced,
and other confounds [e.g. order of use] accounted for)."
Installing a bigger garage door doesn't get the family from the street to the kitchen table any faster if the door to the garage remains the same, but a lot more dead leaves and grass clippings come along.
