CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

2004 Nissan Maxima - AC question

My question is about AC usage in a very hot climate. I live in Phoenix, AZ, a similar climate as Las Vegas, NV and Palm Springs, CA.
Many people I know do not use MAX AC because they think the AC unit is working harder than normal AC. Also, some people think it is wrong recirculate the inside air for MAX AC. I drive on freeways and people that do not use MAX AC are bringing in truck and auto exhaust which I can smell in the car, especially diesel. Also, road dust can enter the car also. I understand the latest model cars have an AC outside air filter but I don’t think many people have this filter changed. Will you please tell people to use the MAX AC to recirculate and cool the inside cooler air and not bring in 110 degree air inside to be cooled. Thank you.

I use max ac until the interior is cooled down and then switch to fresh air to dilute the stale air in the car.

I don’t know who you think you are addressing with your post. If it is Ray we don’t know if he actually looks here .
As for myself , I just let my auto temp system take care of me and where I live we do have really hot weather.

there is no relationship between Max A/C (or any A/C) and exhaust fumes.

There sure is. When max a/c is engaged, that moves the “fresh air door” from outside air to recirculate which in turn minimizes the amount of other vehicles exhaust being drawn into the car.

Incorrect!
When you set your A/C controls to the “recirculate” position (called “Max A/C” on some makes and models), it either shuts down the intake of outside air, or at least it reduces the outside air intake substantially. Whenever I encounter a diesel vehicle that is spewing dark exhaust ahead of me, I switch to “recirculate”, and it keeps most of those fumes out of my car’s interior.

1 Like

The AC compressor doesn’t care where the settings are positioned. Once the AC is turned on the compressor always runs.

You want to set the vent system to recirculate whenever the AC is turned on. This removes the humidity faster from the passenger cabin. But even in the recirculate position, some outside air is drawn into the vent system.

When the vent system is set to max AC, no warm air from the heater core is mixed with cold air from the AC system.

Tester

I was referring to OPs statement that HE can smell exhaust fumes when OTHERS do not use Max A/C.

I think that was a case of bad syntax and sentence structure.