Act 1
giant savings.JPG

Act 2
The sign is certainly missing some information.

Earning Extra Reward Points
For every $1 you spend in the grocery store, you earn 1 Extra Reward Point. So if you spend $256, you get 256 points.

You need at least 100 points to get the gas savings. If you have 100 points, you save 10 cents on each gallon of gas. If you have 200 points, you save 20 cents per gallon. Careful though. If you have 299 points, you still only 20 cents per gallon. They round down to the nearest hundred.

Most cars don't have 30 gallon tanks. For instance, my Hyundai Elantra has a 13 gallon tank. And I never show up to the gas station with an empty tank (that would be tough to do). It might be good to look at the capacity of some sedans, SUVs, compacts, etc.