Can someone lend me a hand here please - I'm lost about the Kroger fuel program.

How many fuel points can you redeem with one fuel-up @ Shell? I keep on reading that the maximum redeemable is 10 cents off a gallon. Why would anybody fill up @ Shell for 10 cents off? I pay 40 cents less for a gallon when I fill up @ ARCO (BP) across the street...

I've also read here that the maximum redeemable is $1 off per gallon which would make much more sense. How does that all work? Unfortunately when I go on the Kroger site and select my store, there's no information available - none as in nada, niente, nichts. It only says "There are no Fuel FAQ's to display at this time. Please check back soon." Haven't seen anything else there since I got my Kroger card (which I actually never got, I signed up online and use my phone# but never received a swipe card in the mail)