GAITHERSBURG, Md. -- GasBuddy has named the retail brands that provided the most competitive gasoline pricing in 2015 based on the data submitted by its large network of price spotters.

GasBuddy Low-Price Winners by Size:
Overall: Costco
For the fourth year in a row, the wholesale club Costco came in at the top as providing the most value. On any given day in 2015, the average Costco was priced more than 19.8 cents per gallon lower than its competitors. It was also No. 1 in 12 different states, the most of any brand, and in the large brand category (100 to 999 stores).
Extra Large (1,000+ stores): Arco
Western marketer Arco takes the prize for the extra-large brands, and third overall, with its gas averaging 17.6 cents per gallon below its neighbors.
Medium (50 to 99 stores): Quik Stop
Fremont, Calif.-based Quik Stop, owned by Kroger, was the most aggressive traditional convenience store, taking the highest slot in the medium class and second overall. Quik Stop priced its gas at 17.8 cents per gallon below competitors.
Small (25 to 49 stores): Rotten Robbie
The Santa Clara, Calif.-based chain has a 13.7-cents-per-gallon average discount over its local competition.
Extra Small (24 or less stores): Food 4 Less
Food 4 Less, a warehouse store grocery chain owned by Kroger, with pumps located throughout Southern California, comes in first for extra-small stores, offering gas for 18.8 cents per gallon on average below regional market price.
Click here to view the complete list and full breakdown.
GasBuddy selected the low-price winners by combing through the 657 million individual price submissions and comparing each brand’s pump offering (by zip code) to the average price of local competitors. It then tabulated the results, rating each brand by the average discount it delivered versus the average pump prices in its competitive area.
GasBuddy is based in Gaithersburg, Md. With more than 53 million downloads, the GasBuddy app helps consumers find cheap gas. The app and website offer real-time fuel prices at more than 130,000 gas stations in the United States and Canada.
Best Value Brands for Gas by State
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