My first thought was to use thicker oil also. Since he's in NC, shouldn't be a temperature issue.I have used this in oil using engines in the past with some success:
You add it at every oil change. You could also try going to a higher viscosity oil such as 10W40 or 20W50 to slow the usage.
The 2009+ is a different engine, 2.5l vs 2.4l. I've no idea if the existing electronics would work with the newer engine. Even if it did the overall expense would likely exceed the value of the vehicle.