How much of a power drain should I notice on a 2010 with 5.3L engine when I have the climate control on? When the AC is on, I notice when the AFM kicks in, and accelerating seems to take a MUCH greater effort than when the AC is off. Comparing this to my experience in another vehicle, I recently drove a coworker's Saturn Sky with a turbocharged 2.0L engine. The AC was on full blast, but I never notice any apparent power drain on the engine (and I never accelerated hard enough for the turbo to kick in).