on an SRT8 it is for premium fuel only.
But the description in the InTune when you select that tune says 87-up octane. That description needs to be changed if it requires premium (92?) just like the factory tune for an SRT8.
How about for a 2009 R/T 5.7? The factory recommends mid-grade (89) for their stock tune. I believe the 5.7 trucks might only need 87 (but somebody needs to verify).