Brakes at the rear seem easy to grind since the change of pads and discs

The fuel consumption indicator seems to be about 1L higher and the brake discs in the rear are significantly hotter than the front after driving. When I drive between houses with an open window, however, I do not hear any grinding noise and there are no vibrations perceptible. Brake behaviour is wonderful overall. Car rolls even if there is a slight leakage. I mean, however, to hear a slight friction. There was nothing unusual about the installation. Saddle and fork still seem to be original and are already a bit finished. Must be changed soon. Can it be that the few hundred kilometers drive normal or not unusual? At least for non-original components (dishes and coverings of ATE)? The coverings seemed to me to be quite well equipped even when installed. Piston was turned back completely. Thanks and greeting