The rate is not hugely generous at 200 SPG points per rental. These convert into 600 Marriott Rewards points or, if you are crediting to Avios, 200 Avios points. You will need to reach certain thresholds depending on your SPG status before you can transfer points to airlines.
Interestingly, this is more generous than crediting a Hertz rental to Marriott Rewards. You only earn 500 points for doing that, compared with 200 SPG points (600 Marriott points) via this route.
One extra benefit is that SPG Platinum members receive free Hertz Five Star status.
However, for most people the most generous way to earn miles and points from Hertz is with Virgin Flying Club. You earn 1,000 Virgin miles per rental as this page of the Flying Club website explains. That is where my occasional Hertz rentals get sent.
(Want to earn more hotel points? Click here to see our complete list of promotions from the major hotel chains or use the ‘Hotel Promos’ link in the menu bar at the top of the page.)