I actually had the opposite today. My PM ink showed 80% all the time. I didn't bother much, as other cardridges were similar. Yesterday, all of a sudden, the printer told me to replace the card very soon. It instantly went from 80% to 20%. I took the card out and it felt, very, very light. The problem is, I have to do prints for customers (before Christmas) and local shops don't have the ink. I ordered some yesterday evening and it should be there tomorrow. It will be very, very tight. Usually, I order when the ink goes to 20%.
Till now I only replaced one cardridge and it was really empty )
Regards, Marco...