There is a loss of approx 7 to 15 hp when you turn on the AC, and every =
time the compressor engages thereafter. Its noticable in all my cars =
that have AC..the EV, my wife's Subaru and my old (now my son's) GTI.

The worst car I've ever owned as far as power loss with the AC on was my =
1973 Mercedes 220D. That car had a 60 hp engine and weighed 4300 =
lbs....so it needed EVERY pony that that oil burner could put out. If I =
had the AC on and needed to climb up a hill or pass a car, I had to turn =
the AC off first...and then once I was done needing the "extra power", I =
would turn the AC back on.

Ric