I could swear that I've seen a topic on this, but I was not able to find it again. Anyway, I just wanted to know what others know about how much impact on MPG makes use of AC. Here is my personal experience. I have my Prius 06 pkg 7 for about 4 weeks now and when I got it, weather was pretty nice here in AZ. Not anymore. In the morning I can still drive with no AC. Not in the afternoon. When I finish work and get into my car, it shows 109-112 for outside temp. I, first, drive for about 5 minutes with my windows rolled down, to bring the inside of the car to outside temperatrue. Then I turn the AC on. It does not matter what temp I set it to, it blows at max for at least 20 minutes before sensors inside of the car start noticing drop of temp. Of course, I have vents pointed at me and I feel compfortable, but AC blows at MAX anyway as the car is still pretty hot. By the time AC starts slowing down (at about 82-85F) my commute is over. Yeah, pretty hot in AZ. Anyway, with AC on and off I've tried taking notes of MFG reading while driving the same road and AC impoact is pretty significant. With AC on and blowing at MAX, flat terrain, MPG never goes above 52; the same stretch of road approximately the same speed with AC off gets me 68-72 MPG. What is others' experience?
Hi CrazyR, Today was my first use of the AC on the drive home. Started at 58.4 on the tank and finished at 58.3 mpg on the tank. So no difference noted. Although, outside temp was 85 F, and just needed the AC to keep indoor temp reasonable while on the highway with the windows up. I am using one of the windshield sunshades available on PC here. Helps a little. Probably would get the side-window shade, except for the cost. It sounds like you need some sort of reflective car cover that that just covers from the windows up. Having the reflective foil on the outside of the glass, and covering the roof too will help tremendously with the inside temp. I have yet to see anything like this though. Has anybody there come up with an automatic mister for cars? It could start misting at 4 pm, and cool down the metal of the car a bunch by 5? I was only to Phoenix once, in July, and by 9:00 am, it was already horendous.
As I picked up my 2005 in October, the first real hot weather was this week in NJ. Well, Thursday on the NJ Turnpike I got above 52 MPG. yesterday (Saturday) I was doing well till I stopped and left the AC on. I dropped to 48 and the battery went real low after less than 5 minutes? I am puzzled, as i thought the battery had a lot more time.
<div class='quotetop'>QUOTE(CrazyRussian @ May 27 2006, 07:57 AM) [snapback]261516[/snapback]</div> Were you looking for following thread? http://priuschat.com/index.php?showtopic=20087&hl= Ken@Japan
<div class='quotetop'>QUOTE(Big Al5 @ May 28 2006, 10:08 AM) [snapback]262012[/snapback]</div> If it's very hot, you'll find the battery can go from 6 to 2 bars in a matter of minutes.. I've seen that happen very often while sitting at long lights. There simply isn't enough battery power to run the A/C heavily for very long.
<div class='quotetop'>QUOTE(Jonnycat26 @ May 28 2006, 02:31 PM) [snapback]262094[/snapback]</div> I ate lunch in my car on a 90+ degree day. I went from 6 to 2 bars in about 10 minutes and two days later the car STILL hasn't recovered. For the rest of that day the engine was CLEARLY working to recharge the battery. Pulling away at lights the engine would roar and the car had little to no pickup. My computed mpg has gone from 47.4 to 46.3 over the last two days. That's with 400 miles already on this tank. I conclude that in a 2006 the AC has at least a 10% effect on mpg when the temps are in the 90s and the sun is out. Goodness, I may actually have to buy one of those super-geeky sun visors and also tint my windows.
Don't know what the difference is. I get a pretty consistant 52 MPG. Of course, I do not usually drive with the AC off. I would rather be comfortable than worry about a small decrease in MPG. Guess I am one of those energy squander's. I have sat in a shaded area with the car running and the AC on for up to 45 minutes. I usually do not pay much attention to it as the ice will kick in when the battery gets to low. Then when I start moving again, the battery will be in the high blue or green range within a few minutes. I think it is great that I can have the AC running and not be using any gas to speak of. Try doing the same thing with a non-hybrid. The engine will overheat in a few minutes, and you will use an enormous amount of gas.
Ok, after a bit of testing I found a way not to bake in the car and not to kill the MPG: do not use AC Auto feature! Whth "AC Auto" on, my MPG goes down at least 10 units, when I manually control AC, it's not so bad: 2, maybe 4 units reduction in MPG. What I started doing is turning AC temp to 80 and fan speed to one less from the middle. Then, when car gets cooler a bit, I change to one lower fan settng. Of course, passenger side AC vents are closed and drives are pointing at me. It's comfortable enough not to seat when it's 115 outside and not too hard for the MPG. When inside of the car cools down even more, I switch to "AC Auto". Damn, it's hot in AZ....
