Luckily ai have a 77. I’m not sold on hard changes that remove outside air choice
1) you lose ventilation
2) you lose the positive cabin pressure to thwart fumes and sewer odors
3) can’t just have fresh air through vents on cool days
4) you lose the “ram air” effect which really helps air volume at highway speeds even with fan on 2.
5) you have ‘type 2’ with max air lower duct already
6) no outside air is bad during heating and def use causing steam up of all inside windows and wetting of wall coverings. Where ‘heat’ would normally work, you would need DEF running comp and costing fuel.
7) if it’s 90 out and 125F inside after being parked in sun, outside air over the evaporator will come out cooler than recirced.
Granted if very high humidity there is less latent heat in recirced air, but have not noticed a difference going to recirc.
Consider before deciding.