SENNINHA
If you are PC Silver then you will be allowed an extra 10kgs under the weight concept. If you have to use the piece concept Silver does not entitle you to an extra piece. I do not know if when flying economy you will be allowed to exceed the 23kg maximum per piece. Flying Business or First you already have the maximum 32kg per piece anyway.
If you are PC gold then it is either 15kg or 1piece extra.
If you are PC Platinum then it is either 20kg or 1 piece extra.
These PC extra allowances are in addition to the standard baggage allowance for your flight. But again maximum 32kg per item.