The cheap filters are what I recommend to my customers most times. The
Grainger pleat says "Recommended Final Resistance 1.0 In WC, High
Initial Resistance 0.38 In"

No residential system I have seen can handle a 1.0" WC final filter
resistance, plus have enough pressure to overcome duct and grille and
coil resistance. Even the initial resistance of .38" WC is too high
for most residential systems. This filter will reduce air flow 10 to
20 % right out of the box. The exception is blowers with Variable
Speed motors, but even they will not be able to handle the 90 day final
resistance of 1.0" WC.

Stretch