[Phase]

Originally Posted by Blacktree

That's true, especially in the summer. Even if the temperature is bearable, the humidity can still make you feel "icky".

Also, the 90*F temperatures are back. No surprise there. I was able to average ~60 mpg the last couple days, with the A/C running. I'm not sure how much of that was the driving environment, and how much was me. But I set the temperature a little higher (78*F). That's the warmest it can get, before I start to sweat. And I noticed the A/C pump cycling off every so often. With the temp set to 75, the pump seemed to run continuously. This will probably vary depending on ambient temperature.

My strategy was a 3-step procedure:
1) Drive for a minute with the windows open, to expel the hot air.
2) Roll up the windows and turn the A/C to max, with the fan on medium/high.
3) After a few minutes, bump up the temperature and turn down the fan speed.

The idea was to remove excess heat and humidity quickly, then run the A/C just enough to maintain it. Obviously, that won't work for short trips. But if you're going to be driving for extended periods (like I do), it might help.

Edit to add: I wonder if adding insulation would make a noticeable impact on HVAC efficiency. When I removed the door skins to replace the front speakers, there was basically no insulation in the doors. I wonder if the roof has any insulation?

I do the same thing. Windows down and max ac fan when first driving to get the hot air out then roll windows back up and put ac at lowest fan speed once I get it to the right comfy temps inside. Insulation helps. Look up thermal jute mats to block outside heat. And obviously tinted windows. I also use a sunshade for windshield. Black cars suck lol