Does A/C impact MPG?

It will effect the mileage - more so in the city and less so on the highway

 

Try using the search function. There have been many discussions on this.

 

short answer - yes
how much impact? it depends on your temp setting and outside temp

 

I see on mine it kills it but 4mpg not a big deal

 

Here is an informative thread about it:
The impact of A/C on MPG | PriusChat

 

You should run the AC to keep you AND the HV battery cool in hot weather as heat is the enemy of a long-lived HV battery.

JeffD

 

Who cares. Stay cool.

 

Wow! That video says a lot about the ac effects on mpg's!

 

I have been running my A/C 50% of the time, and and and getting 54.7 mpg and still driving, 151 miles till the next gas fill up. If I am lucky, I should get into the 500 club. My next goal is to do 550 or 600 club.

 

I should have kept going on my second-to-last tank, I was at 503 miles and it wasn't blinking yet. But I was in the Outer Banks and I didn't want to try to buy gas on the way out of there, so I filled up a couple days early. The computer was reporting something like 57 MPG then, after a long highway trip and a few short trips with A/C running the whole way.

 

Only if you use it! The more you do, the bigger the hit!

 

So far I've noticed no ill effects to my MPG when using my AC. Still averaging 50-51 MPG.

 

As mentioned, A/C impact on MPG is dependent on usage/temperature.
All components in the car ultimately receive energy from gasoline (chemical to mechanical to electrical)

 

Haha, the 3-4 mpg is laughable as people driving over 40 with the windows open get less mileage than with the AC on due to aerodynamics (like with any other automobile, hybrid or otherwise). So yeah, you get better mileage with the AC off...Just don't open the windows!

 

This is incorrect.

 

You're right, in a way...You need to be driving faster than 45 MPH before driving with the windows open gets you less mileage than with the AC on. The findings have been around a lot longer, but this one bases it on a recent SAE study at GM proving grounds:

The study concluded that the more aerodynamic the vehicle, the more drag open windows will create.
Read more at http://blog.gasbuddy.com/posts/The-end-all-verdict-to-A-C-vs-windows-down/1715-457041-563.aspx#A1sqfwLo5hc6MZvS.99

 

Try doing test with your Prius. You'll find that driving with 2 windows down creates less of a mpg hit than using the A/C, particularly during short trips. I've done the test myself many many times. This test has been done by a friend (who works for CaRB in the EV division) in his Civic Hybrid and he found the same results I did.

It is important to make a distinction between the vehicle in question and how many windows are down. With every window down I would agree the A/C is likely less of a hit but who drives like that on the freeway? Every vehicle has different aerodynamic signatures around the window areas. The Prius is still VERY aerodynamic with just the drivers side front window and the passenger side rear window down. That's enough to blow quite a bit of cooler air through the car without upsetting aerodynamics much. Try 4 windows down on a Volt and the wind buffeting is so bad you would expect the back hatch to pop off!

 

We drive a lot without the A/C in hot weather. At slow speeds have the windows fully rolled down, but as speed picks up start bring them back up. I think there's less and less aero impact if they're just cracked a few inches.

I do feel reduced glide or something similar, when A/C's running.

 

Yea. The less you use it and the higher you set the desired temperature, the better gas mileage you will get. I drive around with it on 79 or 80 sometimes when it's 90 degrees out, and the air still feels cold. Don't be that person who sets it at 65 when it's 90 outside, you will drain the hell out of your HV battery.