NEW YORK (TheStreet) -- Penny-pinching car owners can expect to find the lowest gas prices on Wednesdays in South Dakota, Thursdays in Delaware and Maryland and a wide variety of other days elsewhere, a 50-state analysis by market tracker GasBuddy.com has found.
"There certainly can be differences in the best day to buy gas depending on your [location]," GasBuddy senior analyst Patrick DeHaan says. "We found [some national trends], but a rural city in, say, Montana doesn't have to conform to traditional behaviors."
GasBuddy, which uses crowdsourcing to track gas prices at some 120,000 U.S. stations, recently analyzed four years of data to determine which days of the week offer the lowest average gas prices in various states.
The study found that all or part of the weekend (including Friday) offer the best average deals in 35 states and the District of Columbia. Drivers in the 15 other states should stick to gassing up Monday through Thursday.
DeHaan believes weekends offer the best deal in most of the country because energy-futures trading happens only Mondays through Fridays -- and refineries typically only wholesale prices adjust once each weekday evening to reflect that day's closing market price. As a result, gas stations can offer rock-bottom pump prices over the weekend because they know in advance what it'll cost to restock on Monday morning, the expert says.
DeHaan adds that stations know their customers have more time to comparison shop on weekends, making low prices key for competitive reasons.