open windows vs. AC

Open windows create huge drag in addition to drying out your arms. Open the windows up just after you get into the car after it's been sitting a while; keep the AC off, however. After a minute or two when you've blown the hot air out, close the windows and turn on the AC.
If you use the recycle air option on the AC, you will save some energy as the AC will not have to keep cooling "new" incoming hot air. After the cabin has been cooled down, the recycle keeps that same cooled air circulating.

 

I've heard from a couple places, including Toyota itself, that below 40PMH, for max efficiency it's windows, and above 40MPH, it's AC. That's basically the point where the drag of having the windows open overcomes the fuel loss of running the AC compressor.

Of course, that's all probably out the window now (so to speak) since the '04's run the AC directly off the battery and not off the engine itself...

 

I think that it is still just as valid -- just because the AC can run off the battery doesn't change the equation of what uses more *energy*, drag from the windows or AC.

(Unless you're on a long down hill and can keep recharging the battery "for free", of course).

 

interesting window debate. i would think that if only one window is open the drag would be rather minimal compared to having windows open on both sides or at least much less.

it would be interesting to see if there is a real difference. i usually drive with just the vent as i am still hesistant to use the air conditioning. (my corolla noticably lugged down when i engaged its air conditioning)

but hotter weather will soon be here. i might try experimenting with each to see if there is a real difference.

 

I've found that if you drive with the A/C on and the thermostat set higher relative to outdoor temperature that the affect on performance is hardly noticable. For instance, if the outdoor temp is 85, try setting your thermostat at 76 so that the A/C is not working fulltime as it would be if it were set and left at 68. Remember that the A/C compressor is electrically operated and not belt driven as it is in the typical ICE car. The lugging down that you experienced on your Corolla was due to the cycling of the belt driven compressor drawing power from the engine.

 

Let the car do its job. I use the AC with full-time recirculation exclusively. Why keep sucking in fresh soot and humidity from outside? Plenty of oxygen leaks in anyway so it never gets stuffy. Try it!

 

well i live in the Pacific Northwest and this year's weather has been very unusual to say the least. so i frequently drive with the window down. but ill admit i do it so i can hear occasional comments about my car and i t is at speeds of 35 mph or less and i havent noticed any decline in mileage but i havent been specifically looking for it either.

 

yeah, but u don't look cool with the windows rolled up