Total Rewards has partnered with the Shell Fuel Rewards Network to give you a savings of up to 50¢ off per gallon of gas per month.  When you join the Fuel Rewards Network and link it to your Total Rewards card, you earn 10¢ off per gallon for every 500 Total Rewards Tier Credits you earn in a month.  You can earn a maximum of 10¢ off per day, but that can accumulate to the maximum of 50¢ off per gallon per month. Tier Credits do not have to be earned in a single day or in a single location. If you earn 300 Tier Credits at Caesars Palace on one day and 300 Tier Credits at Planet Hollywood the next day, that will trigger a 10¢ discount. Earning 400 more Tier Credits (giving you a total of 1000 Tier Credits earned) at Caesars Palace a few days after that will trigger another 10¢ discount.

Discounts are only good for a single fill-up, so I suggest letting them build up and then using them when you have at least 3/4 of a tank to fill.  The discounts expire on the last day of the month after they were issued. For example, if you earned 500 Tier Points on on August 2nd, and another 500 Tier Points on August 12th, your 20¢ per gallon discount would expire on September 30th.

When it comes time to use the discount at the pump, you will need to swipe your FRN card or enter your account number before swiping your credit card in order to apply the discount.  The Fuel Rewards Network discount from Total Rewards can be combined with other Fuel Rewards Network discounts for even more savings.

You can sign up for the Fuel Rewards Network here.
For more information about how the Fuel Rewards Network works visit their How It Works page.
For more information on the Total Rewards partnership, visit the Total Rewards Alliances Fuel Rewards Network page.

UPDATE:
Total Rewards is ending its partnership with  the Fuel Rewards Program  on  May 31st, 2016