It really depends on the interior and exterior temperature of the car at any given time. When it's really hot inside and out, I'll usually get Max, but sometimes I won't. I've learned to let the car be smart about it - while my usual experience in my old vehicle was to just max the thing out, the CTS seems to be more intelligent about the fan speed that's needed to attain a desired temperature - and I learned to let it do its thing because no matter whether it's trying to heat or cool, it always seems to get the temperature down quickly regardless of how it does it, so I've stopped worrying about whether it's going full tilt or not.