Nothing is ever guaranteed with Hertz, no matter what anyone says It's subject to availability.

Remember, a 2-class upgrade could be from a mid-size (Corolla) to a full-size (Malibu) (bypassing standard/Altima coupe)... or it could simply be mid-size to standard (using the logic C -> YC -> D).

The order is: A B YB C YC D F YF/F6 G H YH I YI, with anything more than one letter being an iffy statement. The upgrade PCs normally only go up to premium though so don't expect anything higher than G. Also, I usually get at least a one-class upgrade anyway (even if it's just to YF from F) without using an upgrade PC, just using the USAA CDP and maybe a $5-a-day-off PC. IMHO you're better off using a money-saving PC -- Hertz treats renters using the USAA CDP very well

-J.