Certain products each week at HV are fuel saver eligible. You might save one cent per item, maybe 20 cents, spend $50 and save 20 or 30 cents. And that savings is per gallon and is cumulative. I've paid 42 cents a gallon (big bags of cheese were on sale and 20 cents per gallon). Good up to 20 gallons.
I was waiting to see if this was available up in MN as I know that its traditionally been a Hy-Vee/Casey's partnership on this. But it's easy to save up Fuel Saver points and pay less than a quarter for 20 gallons of gas.