When the a/c compressor is engaged, it definitely robs power...it's a pretty big load. As mentioned above, the compressor disengages at WOT, although I think there is different PCM logic for when the ac is on...I know I definitely feel a power loss with my ac on (not to mention my fuel economy suffers also)

 

How many of you guys niticing huge power losses with a/c on are running e-fans? I notice less power drop with the a/c on with a clutch fan than with e-fans.

 

yup, when the a/c kicks in, the fans slap a good load on the electrical. I thought it was better with the new 6.0, and it was....but then I got to lookin' one day - I've got a fan out

 

Hmmm, I haven't noticed a difference from when I had the clutch fan and now...haven't really paid close enough attention though.