then why do you have one on your teg unless its very much so not standard.
And for the record, the bmw a/c is very refined so does not suck that much power.(to some of you ) ( tourque to the rest ) lol

But think of it this way it runs of a pull which has to run off the running gear ie crank so it is going to be causing some sort of relative drag. But at the end of the day you cannot put a figure of 10 bhp or 30bhp as the technology is ever moving so it will always be going down. so the only true way to test it would be to get a dyno and run it with it on then off, then bypassed. then we could get a true figure instead of the useless figures being thrown about thanks guys my 2 cents.

 

I'm pretty sure its not 40hp, maybe max 10hp sounds resonable. But my advice is if you are going to run the car real fast.... switch the A/C off... blew a few of the compressor in my previous rides doing about 160mph..

 

Please correct me if I'm wrong but I thought that modern cars would cut-off the A/C automatically when you need high performance (Step on the gas)

 

I've actually reread the thread, and earlier I misread what you had said, and I went down a wild tangent. I digress, I was being an idiot up there.

 

No problem. I've done the same.

No offense taken.