AC vs Gas mileage?

[mark0101]

well not really how much it will affect my gas mileage but would my gas mileage be different if I set on 77 degrees instead of 60 degrees?

 

[unity]

Not really. The AC compressor runs on a pressure switch. I am not 100% sure, but I am pretty sure the compressor runs at intervals based on refrigerant pressures. Those are in turn affect by ambient temperatures.

So if its 80 degrees out and you set it to 65 or 75, the compressor runs the same. For example every 15 seconds.

The difference in temp is really how much outside air is blended in.

 

[mark0101]

thanks I asked because my dad always has it high near 78 degrees with the fan on full blast. I tell him to just lower the temp but he said its better for the gas mileage if he has it set on higher....

 

[bryantaylor]

you have a MPG display. try to drive the same, but with the temps differnt and see if it actually makes a difference.

 

[bbrase]

you have a MPG display. try to drive the same, but with the temps differnt and see if it actually makes a difference.

How much faith do you have in that display?

 

[bryantaylor]

How much faith do you have in that display?

i am thinking too much now, lol

 

[Abbens]

and the people on cnn said if you drive your car with ac on as compared to the windows down your mpg wont be affected. Over here in nyc for the past few days it was high 90s. my ac was on and it did affect the mpg on street and hwy

 

[JMiles_T]

Yep; that 'window down = A/C on' thing is a myth.

The A/C always uses more gas.

The instant MPG gauge can help show that there is a difference.

With the Climate Control turned off, get on the highway, on a flat portion of road and set the speed control to 55 mph or so, and look at the Instant MPG display. Then hit "MAX A/C" and see what the display shows.

 

[unity]

Might have read/heard that wrong.

Above 55 or so, AC is the way to go. Below that windows work down the best.

 

[Tricky-Dick]

Always use "recirculate" button. Easier to cool "cooled" air then "outside" air.

 

[mark0101]

Always use "recirculate" button. Easier to cool "cooled" air then "outside" air.

would that be Max ac on ours or just automatic?

 

[Tricky-Dick]

I would believe Max.

 

[mark0101]

I thought the only thing Max AC did was let the air past through the filter so if there is a bad smell outside you can switch it to Max. I guess its for recirculating the air too.

 

[Moes8]

I thought the only thing Max AC did was let the air past through the filter so if there is a bad smell outside you can switch it to Max. I guess its for recirculating the air too.

most cars dont have a filter,

Max is to cool the inside air without any outside air mixing in,