I find it is low end power that is consumed (cars become bog slow in traffic). If you stomp the gas, the a/c will take a rest for a few seconds. That's normal. The automakers certainly know the a/c needs to shut off when full power is needed. The a/c allows long road trips in hot weather and actually hearing the radio at highway speeds (and beyond!) A great invention, if it is working
Maybe driving the compressor electrically would lower drag IF the power consumed is less than mechanical drive. Some hybrid cars have that type, I think.
