Originally Posted by Pretherius
I don't have concrete real-world numbers, unfortunately. But my experience has been just what you said: a 2 or 3 mpg hit. I think if you read up online you'll see that's roughly the conventional wisdom, too.
Thanks. Yeah I'm still happy since I'm still getting the EPA combined rating but I guess I was really getting used to beating it by 2-3 mpg. I might try to do a controlled test this weekend, maybe a 5-mile loop w/ AC and another one without to determine the actual hit.