Kroger has doubled the maximum number of “Fuel Points” that shoppers can earn for discounts on gas through a chain-wide summer promotion running May 27 to Sept. 30.Store loyalty cardholders earn points for gas by purchasing groceries or gift cards and filling prescriptions. (See Related Articles.) Every $100 spent earns a discount of 10 cents per gallon at Kroger gas stations and partnering Shell outlets. The savings are normally capped at $1 per gallon but have been increased to $2 during the promotional period.“In addition to everyday low prices in all of our stores, this is another way we're rewarding our customers for choosing to shop with us," senior vice president of merchandising Michael Donnelly said in a media release.Kroger is touting the promotion with P-O-P materials (some of which carry QR codes), carousel ads on chain home pages, circular features and Facebook status updates. TV and radio spots support in some markets.