2010 CTS4 sedan
I was about to point that out - AWD really only has the FE1 or FE2 suspension. It really is a limiting factor. Great traction but...Given you have 19" wheels it is likely you have FE3 suspension as well. While I understand your budget concerns, I'll go ahead and mention that these cars (with FE3 in good condition) are capable of taking advantage of the very best tires available. Michelin PS4 is a known good one, although there may be others.
Good tires are not wasted on the CTS with FE3. Lesser tires, if used, will be your limiting factor.
Edit: Just remembered the OP has AWD, so the suspension tuning may be FE5 (AKA FE2 with big wheels?). So I don't have personal experience with this setup.