4Runner Climate Control and MPG

[jpalaska]

When the climate control is put on 'auto', the air conditioning comes on too. I always then turn off the a/c.
Wouldn't leaving the a/c on all the time in 'auto' mode lower the truck's mpg?

JP

 

[toto]

Yes, it would affect MPG.

But know that just because the A/C light is on doesn't mean the compressor is running. If it's near or below freezing outside, it can't run and the computer won't try. In Auto mode, the A/C light means that the A/C is "enabled" if the computer wants it. Usually the computer does want it, though, as a dehumidifier in either warm or cool weather.

 

[toytrukn78]

Yes, it would affect MPG.

But know that just because the A/C light is on doesn't mean the compressor is running. If it's near or below freezing outside, it can't run and the computer won't try. In Auto mode, the A/C light means that the A/C is "enabled" if the computer wants it. Usually the computer does want it, though, as a dehumidifier in either warm or cool weather.

I always wondered that myself, and turned it off when I wanted heat. That makes sense though, just like auto thermostats in the house only uses what it needs when it needs it. Thanks for the insight.

 

[tedcool]

I wondered about that too!

There's nothing in the owners manual about it that I could find. Has anyone found anything 'official' from Toyota about it?

 

[toto]

Experience aside, the best thing I could find is a snippet from the 2004 RX 330 Owner's Manual:

The air conditioning does not work if the outside temperature is lowered down to around 0 C (32 F).

If the system is used for ventilation, heating in dry weather or removing frost or exterior fog on the windshield, turn the air conditioning off once it is no longer required. This will improve fuel economy. The air conditioning can be used for year

 

[icantsee]

Yes...using A/C will affect your MPG.

I've been to places like Davis & San Jose in California and it can get scorching hot. From comparison back home...I only use A/C if it's scorching hot.

 

[alaskaman]

i do the same I turn the a/c off after i turn it to auto unless it is hot which it can be in sactown. the only other reason i use the ac is to de fog the interior windows which seems to be less in this vehicle than my 97 4Runner.

 

[josh220]

I use the A/C any time it gets hot or humid inside, who cares about MPG if you aren't comfortable in a 30k+ vehicle.