car power lost

Same reason you lose power when going up a steep incline, extra load on the engine. When the clutch kicks in for the compressor, the engine must work on compressing the gas and does nothing to assist in the running of the engine.

Very simple answer, the question is why the car loses relatively much more power than a window air conditioner 1 TON capacity with and EER = 10, that consumes only 1.6 Hp. In a 100 hp car will feel lost about 40 Hp

an auto air conditioner must be much more than 1 ton AC, I would estimate on full size car it must produce a minimum 55,000 BTU cooling