Radio volume across sources?

How consistent is the radio volume when you change sources? I like a local AM program and some of the XM offerings. On my 2015 Prius to get acceptable volume levels requires around 20 on XM and 43 on AM. If you forget to adjust before changing from XM to AM it isn't pleasant. I have no clue why they can't get it closer among sources. So I'm curious if I decide to go to the Volt if it will fix that annoyance.