A/C Usage and Impact on FE

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Originally Posted by bowtieguy

typically it is comfortable enough to just run the fan in the am, even perhaps cracking open a window. with the heat of the afternoon, and subsequent quicker warm-up, my FE is generally very near the am run, even w/ a/c on.

Yes, it was quite surprising how much my last two fill ups varied based on how I used the a/c. Of course, it took me realizing the drop in FE by 5 MPG.

I typically have been able to get another 40 miles than where I was when I filled up again. My VX has a 10 gallon tank(?) and I've been putting in 5 gal/stop to get an accurate idea of how much gas I'm using. Typically, for every 5 gallons I could reach 200 miles solid until the A/C had to come on. After that I got barely over 160 before needing to fill up. You can't always rule out a tank of bad gas either. Now I'm at 120 with 2 1/2 gallons left.

I don't want to run the tank bone dry every time; as contaminants tend to settle to the bottom of said tanks, but since I just got the car I need to know what it can do now compared to the work being put into the car. Long overdue, but educational. Of course, with 240k ish miles, it will need SeaFoam and Lucas in the tank from time to time anyway. I'd rather burn out whats in there as far as those additives before replacing the LAF sensor that's shot...but all of that is another story.