AC and MPG and scangauge

[dkmiller68]

For those of you that have a scan gauge. What does it say when you put on the AC in regard to mileage...I assume it gives you a real time estimate of MPG? Thanks in advance.

[Techy-D]

For those of you that have a scan gauge. What does it say when you put on the AC in regard to mileage...I assume it gives you a real time estimate of MPG? Thanks in advance.

I did this test when I got my ScanGauge. It shows about 2MPG less (On the realtime readout) when the AC is on. I haven't left the AC on long enough to watch what it shows when the temperature is cool enough to cycle the compressor, but I'm sure it goes back to normal while the compressor is off.

[etlsport]

just tested HP readings with and without AC

at idle in park with the brake applied (not moving) i was using 8.0-8.1 hp... turned the AC on and that number went to 11.6-11.8 hp

and for those with electric fans.. there was no noticable difference between hp readings with my 30 amp fan on and off

[workmeistr]

I tested this on the highway today, My MPG drop by 1 to 1.1 MPG when first turning on the AC. Strangley, when the compressor cycled on/off, I still only had a .8 - 1 MPG loss. The cycling on/off didn't seem to lower/raise accordingly.

[Techy-D]

I tested this on the highway today, My MPG drop by 1 to 1.1 MPG when first turning on the AC. Strangley, when the compressor cycled on/off, I still only had a .8 - 1 MPG loss. The cycling on/off didn't seem to lower/raise accordingly.

You beat me to the punch. I did the same thing just to see, and it hardly changed when the temperature seemed to be satisfied. Not sure what it means. I guess the compressor stays pulled in at some level.