fourfive
Senior Member
All the filters are very close. In general they knock the flowrate down by about 1/2 of the fan setting. So with the fan at 2 it's like having the fan at 1 without a filter. The Russia filter flows the best but only marginally, and the Merv4 stuff is a teensy bit better than the foam.
Wow nice work. Since the air flow rate is decreased with the cabin air filter installed, have you noticed a difference in cooling efficiency on hot days?