How much does A/C affect mileage?

cattygurl · 05-15-2006, 06:12 PM

How much does the AC affect mileage? I am driving through the desert if all goes well and I end up with my insight in Phoenix. I know I'm going to have to use a/c driving back to cali- any tips on how to keep the mpg high using a/c aside from driving slow?

I am so excited, I just can't wait. If I don't get this car in Phoenix, I'll be crushed, but I'm not going to let the dealership take advantage of me.

jbrasure · 05-15-2006, 06:25 PM

Make sure you use Econ mode, set the temperature as high as you comfortably can, and manually turn up the fan speed to a higher setting. That should help.

goat961 · 05-15-2006, 06:44 PM

alson while in econ mode you can select ac or no ac... if you cycle between them it works very well since you only need to put the ac on for a couple seconds to get almost a minute of cold air (depending on temp i guess).

also, try to run the ac going down- especially while coasting as your mpg won't be effected there. don't use it going up hill.

HafNHaf · 05-15-2006, 09:46 PM

in my insight it costs about 10 mpg. i do it the way goat said, with very little impact on mpgs. be aware: a setting higher than 60 degrees seems to just mix in hot air with the a/c air. i dont know if it causes the a/c compressor to cycle any shorter. seems counter productive to me.

**highwater** · 05-16-2006, 01:43 AM

I leave mine set on bone chillin' cold, and manually cycle it off going up hill. You will get nice cool air for quite awhile after you turn it off. I have seen the same yucky mixture as HafNHaf if i try using the thermostat. This is of course, when I actually use the A/C

.

Randall

**b1shmu63** · 05-16-2006, 02:04 AM

Excellent tips.

I do strive for mileage, but if it were me driving through the desert, and it was hot as....well, Phoenix. I'd enjoy the AC and smile knowing I'm still smoking anything else out there for mileage. If it isn't too hot around here, that's 50 out of 52 weeks of the year, I just open the passenger side window the tiniest amount dial the AC to cold and make sure it is really OFF by hitting the Econ button the majical 2 times.

Still, if you want to tell your friends how you crossed the continent on one tank of gas when you get back, you can always take along a spray bottle of water, like Uber hypermiler Wayne Gerdes used to do!

Enjoy the trip!

05-16-2006, 02:36 AM

What's this about hitting the Econ button two times?

jbrasure · 05-16-2006, 02:49 AM

I have a CVT, and I don't think the AC affects it as much as the stick shift(probably because stick shift get's such better gas mileage.)

Running the AC heavily in "Auto" mode probably drops my mileage by 5 MPG. Running it in "Econ" mode only drops the mileage by 2 or 3 MPG. It depends on the temperature though. There are some days when the AC barely runs, and it hardly affects the mileage at all.

James

**b1shmu63** · 05-16-2006, 02:52 AM

The first time you hit it the AC goes into econ mode which means the compressor and engine shut down when the Insight is stopped. The second time you hit it it actally turns the AC OFF. Otherwise you can have the AC compressor on and be blowing warm air into the car.

This is great for defogging the windows but it really hammers the mileage, (spoken as a hypermiler wannabee). I suspect that many people are blissfully driving around with the AC compressor running and are unaware of it, wondering why they can't achieve lean burn!. I searched for documentation on this and could not find any. After two or three days of frustration, where I was ready to pull the AC fuse, I happened upon this discovery. If any one out there can point me to documentation on this, great. I believe the other way to run the fan without the AC is to push the fan speed button only. Not sure.

HafNHaf · 05-16-2006, 06:48 AM

a few weeks ago i installed a bright blue LED on the dash that is powered from the a/c compressor relay. whenever the compressor is on, the LED is glaring at me from the dash. its a great reminder to turn it off!