Timing your gas purchases can make a surprising difference in your fuel expenses. According to data from GasBuddy, gas prices are not static throughout the week—they follow predictable patterns influenced by supply, demand, and consumer behavior. Knowing when to fill up can help you save several dollars over time, especially if you drive frequently.

Here’s what the latest research and real-world trends reveal about the best times to buy gas.

Best Day to Buy Gas: Monday

GasBuddy’s annual price analysis consistently shows that Monday is the best day of the week to fill up. Prices tend to be lower early in the week, as stations reset after the weekend rush and before midweek price hikes.

• Why Monday? Demand is lower, and stations are often trying to attract weekday commuters.

• Tip: Aim for Monday morning if possible, as prices can start rising by the afternoon.

Second Best Day: Tuesday

If Monday is not an option, Tuesday is your next best bet. Early Tuesday often maintains similar pricing trends before the midweek uptick.

Worst Day to Buy Gas: Friday

Avoid filling up on Friday if you can. Gas prices typically rise heading into the weekend, when more people travel for leisure, errands, and short trips. Stations capitalize on this increased demand.

• Why Friday? Weekend road trips and paydays lead to a surge in fill-ups.

Worst Time of Day: Late Afternoon and Evenings

Aside from weekly trends, gas prices are more likely to spike during late afternoons and evenings. Stations may adjust prices based on demand, especially as commuters head home from work.

• Tip: Fill up in the early morning—preferably before 10 a.m.—to lock in the best daily rates.

Holiday Weekends and Gas Prices

Leading up to holiday weekends like Memorial Day, Labor Day, and Fourth of July, prices often climb sharply. If you plan to travel, fill up several days early to avoid paying peak holiday rates. GasBuddy has found that prices can increase by as much as 10¢–25¢ per gallon right before major holidays.

Other Factors That Affect Gas Prices

• Regional Trends: States with lower taxes or competitive markets (like Texas or Missouri) typically have more stable prices.

• Weather Events: Hurricanes or severe storms can disrupt supply chains and lead to sudden price spikes, particularly in coastal states.

• Market Volatility: Global oil prices, refinery issues, or political instability can cause unpredictable changes at the pump.

Pro Tips for Maximizing Savings

• Use Price-Tracking Apps: Apps like GasBuddy and Waze can help you find the cheapest station nearby.

• Top Off Smartly: If you notice gas prices are lower early in the week, even if your tank is not empty, topping off can be a strategic move.

• Combine Savings Tools: While this post focuses on timing, combining good timing with rewards programs like Shell Fuel Rewards or discounted gift cards from apps like Fluz can push your savings even further.

Final Thoughts

Buying gas is one of life’s unavoidable expenses, but when you fill up matters more than most people realize. By timing your visits for early mornings on Mondays or Tuesdays, and avoiding late afternoons and holiday weekends, you can consistently save a few cents—or even dollars—on every fill-up.