04 XC70 - Double cabin air filters bad?

[P2metoo]

I bought a normal 1" filter by mistake before getting the 1½" carbon filter I wanted. That empty 1" slot is tempting me to try double filtering. Anyone ever tried that or seen if it is too much resistance for the blower? Probably won't risk it but thought I would check for kicks. Cheers!

[abscate]

Just do one. Technically you should reprogram the HVAC for the filter of choice , you can get away with moy]t doing this in the cool NE, you might not get good AC in Alabammy!

Jim warned me about this when I bought my P2 from him in 2014