In search of diaper deals and cheaper milk, Erin and Chris Smith joined their local warehouse club. To their surprise, the Cary, N.C., couple found their biggest savings at the pump: They saved about $200 last year at the club’s filling station, which discounts fuel for members. Cheaper gas is becoming popular territory for warehouse clubs and supermarkets – a bigger play for customer loyalty, and a new opportunity to pad their own bottom lines.
Warehouse clubs and grocery chains are increasingly offering discounted fuel at their U.S. stores — often up to 10 cents or more per gallon lower than other stations a few blocks over. There are about 5,000 of these so-called “hypermarts,” up 37% over the last five years, with another 200 expected to open next year, according to EAI, Inc.,...