It's hot out here in So Cal, and my car's working overtime. I like it cool in the car, so I have the A/C on constantly.

What type of mileage affects do you guys see with A/C?

I am losing 5%-10%. That's significant, even though I am not the hypermiler many here are. Typically I'll see around 40mpg. Sometimes more, sometimes less. Recently, I've been seeing 37ish. I was worried, so I checked tire pressure, etc.

To experience the effect of A/C on my car, I turned it off and on a couple of times while going up a slight grade on the freeway at 60 mph. Big difference!

Anybody else notice changes?

Thanks,
Lansing