Does A/C effect the power?

[chiefsalami]

The AC compressor is driven off of one of the pulleys that is on the same belt as the crankshaft. It is spinning all of the time on that pulley. However, when the AC compressor is on, there is a clutch that is engaged that puts it onto that pulley as a load. So the increased load slightly bogs down power available to turn the wheels. You will feel some effect in any car when the AC compressor is on. Now if you don't mind unconditioned (often also not necessarily cool) air, you could have the (electric) fan on, but turn off the compressor and you won't feel any difference in power.