Motorists who are seeking cheaper gasoline prices should fill up on Mondays, which can lead to saving hundreds of dollars each year, according to analysis conducted by GasBuddy.com, a Boston-based provider of retail fuel pricing information and data.

Gasoline prices have been rising nationwide recently as crude oil prices continue to experience volatility and have fallen to $48 a barrel. Current gas prices have reached their pinnacle in the past 19 months and a reprieve will not occur in the short-term as consumers face the expensive summer driving months, said Patrick DeHaan, a senior petroleum analyst for GasBuddy.com.

An analysis of fuel price data during three years determined that average gas prices were the lowest on Mondays. The worst day for drivers to fill up is Thursday.

"It wasn't a huge shock that we saw these results," he said.

The weekly report issued by the Energy Information Administration (EIA), the independent statistical arm of the Department of Energy based in Washington, D.C., on Wednesday could also play a factor in gas prices.

"The rise in average prices toward the weekend could be to blame on an influential report from the EIA, which could push prices higher the day after, depending on if data in its report is as expected or a surprise," said DeHaan.

Commodities trading falls to much lower volumes over the weekends. Many gas stations opt to "let it ride" over the weekend which can result in the lower prices by the beginning of the week, he said.

"There's some deals to be had on Mondays compared to other days of the week," DeHaan said. "Gas isn't something that's fun to buy, so I always try to spend less and encourage motorists to fill on the cheapest day and also shop around for the lowest price while they're at it."

Refiners and distributors typically do not adjust prices until after commodity markets open on Monday since trading in the crude oil markets is minimal over the weekend, said Bruce Bullock, director of the Maguire Energy Institute at Southern Methodist University's Cox School of Business in Dallas.

Gas prices vary widely through each region of the U.S as the amount of state tax differs. The analysis by GasBuddy determined that Thursday is the most expensive average, making it the worst day to purchase gas. So far this year, Monday is the best day to fill up in 23 states. The data found that during last year, Monday generated the lowest average gasoline prices in 36 states, while eight states saw Tuesday leading the cheapest prices.

The analysis also found that Monday produced the lowest gasoline prices in 22 states in 2015 while in 2014 Wednesday offered the cheapest average gasoline prices.

While price variations can occur widely depending on the state or the year, drivers who want to spend less money on gas should aim to purchase fuel earlier in the week, said DeHaan. If all consumers purchased gasoline in the U.S. on Thursday compared to buying it on Monday for one year, they would spend an extra $1.1 billion.

Prices have been rising as refiners are switching over from the cheaper winter blend fuels, said Bullock. The American Petroleum Institute (API), the trade group, reported that March deliveries were the second highest ever recorded.

While prices are up 13 cents compared to March, according to AAA surveys, drivers can still find deals since the spread can be as high as 15 cents per gallon in the same market, he said.

"The Krogers, QuikTrips, Murphys and Speedways usually offer the best deals," said Bullock.

Gas prices could decline in the near future since inventory levels will rise, said Chris Faulkner, CEO of Breitling Energy, a Dallas oil and gas exploration and production company.

OPEC's agreement to slash the production of oil has kept the supply artificially low and forcing prices northward, he said.

"However, we continue to see global crude supplies hovering above the five-year average due to the increase in supply from the shale oil drilling restart," Faulkner said. "This is causing oil prices to remain lower than expected and keeping gasoline prices in the same boat."

OPEC is preparing to drop its production caps, which will allow its member countries to "pump out more oil, causing global pricing pressure," he said. "While this sounds crazy, I feel confident it will happen. If we see the cap removed, oil prices would re-test the 2016 low of $26.05 and this means consumers could see a 50% discount at the pump."