I feel little power loss(kind of heavyness) during AC switched on but the loss is less after engine gets heated up. I never felt any problem with cooling in Bombay and Pune. No problem on the highway either, infact its no power loss there.I always avoid switching on the AC when engine is cold. I never felt any power loss problem while driving uphill fully loaded (four adult (including driver))during my recent trip to Mahabaleshwar but with AC being switched off (I never switch on the AC when the car is loaded driving uphill). recently after changing the air filter i felt better response.