AC compressor dragging?

VolvoFreak · Post by **VolvoFreak** » 18 Jul 2005, 08:04

I'm curious to know how much drag the a/c compressor puts on the engine while engaged. Reason I ask is that when I run with the a/c on, I go from around 29mpg to below 20 and the engine seems to hesitate while running. It actually almost feels like it backfires. If I'm at idle and look at the tach, it will be at 800rpm, then dive down to between 300 & 400 and kick back up - almost like a cycle.

Jot · Post by **Jot** » 18 Jul 2005, 08:19

I have heard it takes about 5 HP to drive the AC . Yes it will effect the MPG

VolvoFreak · Post by **VolvoFreak** » 18 Jul 2005, 08:21

I understand that it will effect the mpg, but that much? I'm talking more than 10mpg's...

VolvoFreak · Post by **VolvoFreak** » 18 Jul 2005, 11:10

Update... Just took it to my mechanic and got back. Problem was that it was never filled properly when I got the car in the 1st place (back in Feb). He recharged it and it's perfect now

I never realized how bad the engine will run with an undercharged a/c!