We do leave balances sometimes to show usage. But this month its 0%. We have tried it both ways. Never seems to matter. Maybe 2-3 pts difference. We even tried having a 5% utility for a few months straight and it didnt help. Her average age is 4 years. And then she is an authorized user on 3 of my cards that I have been a cardholder since 2002 on each. When it breaks down the FICO score it says Recent missed payment as the only negative. And the reason it is recent, is because she paid it when they told her to. It was a few years old, but her paying it made it newer. We are still working to get it off, because it is actually a big mistake.
As far as the mortgage and installment thing. We own both our cars outright. The next car we buy we plan to put in her name on the loan. So hopefully that will help. The mortgage, I got before we were married, so its just in my name.
