How would always running A/C compressor effect gas economy?

[Triple S]

This thread got me to thinking.
Air Conditioning is always running

We have seen a lot of threads about very different gas economy ratings. Is it possible those with lower MPGs are just running around all the time driving the A/C compressor?

I'm the kind of guy who drives around all the time with the switch set on floor and defrost, be it in the middle of the winter with the fan on high and the temp on high, or in the summer with the fan off and the temp on cold. I can see people running their compressor all the time and maybe not knowing it...

[BigSkiff]

Originally Posted by Quad T

This thread got me to thinking.
Air Conditioning is always running

We have seen a lot of threads about very different gas economy ratings. Is it possible those with lower MPGs are just running around all the time driving the A/C compressor?

I live in South Florida. I run my A/C 99% of the time. I carry 800 pounds of equipment in my truck, always. My overall gas mileage to date is 14.5 city and 17.9 highway.

Running your A/C versus not running your A/C should make a diffrence. It takes a little more power from your engine to run the A/C so it should use a little more fuel than if you do not run it. Also, to those who live in cold climates and run your defroster; when your defroster is on so is your A/C. It helps remove the moisture from the windshield and inside the cab.

[Triple S]

Originally Posted by BigSkiff

Also, to those who live in cold climates and run your defroster; when your defroster is on so is your A/C. It helps remove the moisture from the windshield and inside the cab.

Although this may be true, around here there is no reason to run the A/C when a minute of just running the fan will do the same job. I'm one of those people who just plain hate A/C, the only time I run it in my truck or car is when it is really hot outside and I'm in a long sleeve dress shirt and tie.

[Squid]

Originally Posted by Quad T

Although this may be true, around here there is no reason to run the A/C when a minute of just running the fan will do the same job. I'm one of those people who just plain hate A/C, the only time I run it in my truck or car is when it is really hot outside and I'm in a long sleeve dress shirt and tie.

I don't know why? But if I have more than one person in the truck I have to run the defroster to keep the windshield clear when it's cold/cool outside.( The fan won't get it done.) I have never had to do this with any other vehicle.

[Sammy Sandbag]

Originally Posted by Quad T

Although this may be true, around here there is no reason to run the A/C when a minute of just running the fan will do the same job. I'm one of those people who just plain hate A/C, the only time I run it in my truck or car is when it is really hot outside and I'm in a long sleeve dress shirt and tie.

Let's not forget:

Quad T
Registered User



Join Date: Mar 2004
Location: Upstate, NY
Posts: 561

[grunkster]

VERY interesting!!...I did not know that running defrost (which i've been doing in combination with heat the WHOLE winter), runs the AC compressor...hmmmm. I'm gonna try some experimentation.

[Triple S]

Believe me, I'm well aware that where you live will make all the difference in the world on how your windows steam up, but that is not my original question.

I live in Upstate NY, one of the snowiest cities in the US and during the winter it is so darn dry my fingers split from severe cracking, and during the summer we only get a hand full of muggy days, thus no real need to run the A/C to keep the window clear.

Now, back to out previously scheduled program on fuel economy or the lack there of...

[Squid]

Originally Posted by Quad T

Believe me, I'm well aware that where you live will make all the difference in the world on how your windows steam up, but that is not my original question.

I live in Upstate NY, one of the snowiest cities in the US and during the winter it is so darn dry my fingers split from severe cracking, and during the summer we only get a hand full of muggy days, thus no real need to run the A/C to keep the window clear.

Now, back to out previously scheduled program on fuel economy or the lack there of...

100 miles a night, 6 nights a week, and I've noticed no difference. 17MPG neighborhood every tank without a load. (and just to clarify, maybe it's just the heavy panting of my passengers in this truck that is causeing the problem?)

[jdmartin]

maybe it's just the heavy panting of my passengers in this truck that is causeing the problem?)

I vote for this, because my 2 dogs (lab & lab/rott mix) fog up my windows pretty good when they're in the truck. When it's just me and my wife I've never noticed any fogging (accidental fogging, that is

[TONEYTTITAN]

Originally Posted by Squid

100 miles a night, 6 nights a week, and I've noticed no difference. 17MPG neighborhood every tank without a load. (and just to clarify, maybe it's just the heavy panting of my passengers in this truck that is causeing the problem?)

you should change you name to STUD jk.

[SUBTITAN]

There will be a minimal hit on MPG with the A/C on, but not enough to worry about. Running with the windows down will increase drag and effect MPG more than running A/C. I believe most newer cars/trucks have the A/C running on most settings, and some such as my Ranger doesn't have a light to let me know it's running.

[Triple S]

Originally Posted by Squid

maybe it's just the heavy panting of my passengers in this truck that is causeing the problem?)

That was good...

Thanks for your reply, seems maybe I'm not onto anything at all... Oh well, it was a nice try.