Google Maps' Gas Price Data Comes From Third-Party Provider OPIS

Google Maps relies on third-party data providers to fill in gaps in its knowledge. One such gap is gas prices, which are provided by OPIS (Oil Price Information Service), a Dow Jones-owned firm that sells fuel pricing data.

The data from OPIS is accurate for getting a general picture of what fuel costs in an area, but may lag reality by a day or more for single stations due to constantly shifting gas prices.

Nearly one in four American gas stations transmit their prices directly to OPIS every day. The firm also builds averages from reconciled credit card transactions, effectively using consumer payment records as price reports.