Are ‘Gas Sales’ at Greater Binghamton Gas Stations Worth It?

I waited in line for a 'gas sale' yesterday for 15 minutes. While I was sitting there, I decided to do the math to see if it was really worth it. The answer I came up with is...no!

This gas station's 'gas sale' had gas for 3 cents cheaper than usual.  I have a 20 gallon tank. To fill it during a 'gas sale' would save 60 cents. Actually, to make it worth it, I would have to have a 100 gallon gas tank in my truck. Do you wait in long lines for gas sales?