What Is the Best Day of the Week to Buy Gas?

Gas prices can fluctuate frequently, including over the course of the day. For frequent commuters, folks with longer commutes, or even families with several drivers, savings over time can add up based on price differences.

This leads to the question of what day of the week is best to buy gas.

While it's true that Mondays in the US (and Fridays) tend to be a couple of pennies less per gallon than the other days of the week, this trend will likely be unreliable. Gas prices are a result of numerous factors that aren't always predictable, including oil prices, operations of local refineries, transport costs, competition, seasonality, unpredictable weather, and demand.

This guide is meant to help readers of ENG366 understand the most common patterns for the weekday pricing of gasoline, when it is typically the most advantageous to buy, and techniques that offer additional potential savings beyond only timing your purchases to a particular day of the week.

What Is the Best Day of the Week to Buy Gas?

Generally, Mondays provide the best opportunity for drivers to save money on gasoline.

Historically, fuel price analyses show that gas prices tend to be at or near their lowest levels of the week on Mondays, with Fridays typically being the second lowest.

There is no rule that gas stations have to sell gas for less on Mondays. Stations could easily sell gas for more in Texas on a Monday and less in Florida, so prices would be based on demand for gas and the price of gasoline at the wholesale level for that station.

Mondays tend to be good days to buy gas, but it is more important to shop around gas stations and compare prices to ensure you are getting the best deal. Variations in prices based on the region are usually much greater than the differences on any particular day of the week.

The U.S. Energy Information Administration tracks reported retail gas prices. They show large differences in gas prices throughout the country for all regions of the US and can be used to compare gas prices on a regional level to assist in answering what days are best to buy gas.

Why are Mondays good days to buy gas? Demand for gas is likely to be low Mondays through Fridays, since most people tend to work during the week and do not have to drive as much as on weekends when people may travel to go on a trip or go to an event.

Differences in gas station demand and competition affect retail prices. Depending on the location of a gas station, retail prices may be lower compared to other locations, even if it is on the other side of the country. Competitive areas may have gas stations that are side by side and have different prices.

This shows that the day-of-the-week technique must be a small aspect of your fuel-saving plan, rather than the bulk of it.

Is Friday a Bad Day to Buy Gas?

Friday can be good too.

Many people associate Friday with expensive gas. People reason that since gas goes up in price to prepare for weekend travel, Friday is an expensive day to buy gas. There is evidence to show that Friday and other weekdays are actually some of the cheaper days to buy gas.

AAA usually reports that Monday is the cheapest day to buy gas, while Friday is the second cheapest.

That doesn’t mean that Friday gas prices are always low.

Look at travel weekends such as:

• Memorial Day
• 4th of July
• Labor Day
• Thanksgiving

At these times, you should look to avoid gas purchases on these travel weekends.

There is no absolute weekday you should avoid buying gas. If market forces aren’t acting, Friday prices may not be much more than Monday prices.

Prices of crude oil aren't the only reason for gasoline price increases, they can also be attributed to

• refinery shutdowns
• pipeline interruptions
• hurricanes
• regional fuel shortages
• geopolitical events
• changes in gasoline blend seasonality

The U.S. Energy Information Administration (EIA) publishes gasoline price data for the U.S. on a weekly basis. This data shows the speed at which price changes occur at a national and regional level.

Therefore, skipping a more expensive gas station may be a better use of a consumer's money, as opposed to avoiding an expensive trip.

Gasoline density typically does not vary significantly by time of day. Most of today's gas stations store fuel below ground. It is more important to be aware of price changes than to buy gas at 7 a.m. rather than 4 p.m.

Prices at individual stations may be updated more than once during the day. The best strategy is to see what gas prices are before even leaving home.

Knowing this makes it obvious that there is no ideal weekday to purchase the cheapest gas.

Crude Oil

Oil prices influence the price of gasoline. When oil prices increase, so do retail gas prices. Conversely, when oil prices decrease, retail gas prices may also decrease.

It can take time for prices to adjust after a disruption.

Refinery Costs and Capacity

In order for crude oil to become gasoline, it must be processed by a refinery.

A disruption at a refinery (through scheduled or unscheduled outages) in a particular region can impact the supply of gasoline in that region.

Limited supply means prices of gasoline could increase.

Transportation and Distribution

Gasoline must be transported from refineries to terminals and then to individual service stations.

Transportation costs can also vary based on how far gasoline must travel, the infrastructure, and how the gasoline gets from the refinery to the terminal (where it is stored) and to the service stations.

State and Local Taxes

There are also differences in gasoline taxes on a state-by-state and local level in the U.S.

Two individuals purchasing gasoline of the same type at the same price may pay dramatically different prices for the same gasoline if they happen to be in different states.

Seasonal Fuel Changes

There are changes in gasoline quality and formulations based on the season.

Competition Between Stations

Gasoline prices can also change based on the competition in the area.

Generally, gasoline prices will be lower at a station that is in an area that has many competing gas stations.

In remote areas, where there is less competition, gas prices can be higher.

This means where you buy gasoline can impact the price more than when you buy it.

Should You Wait Until Monday to Fill Up?

It depends. If your tank is almost empty, you shouldn't wait until Monday to fill up just because gasoline prices may be lower on that day.

Driving a far distance or letting your gas tank get almost empty to take advantage of lower prices on Monday isn't wise.

Using this strategy could potentially cost you more in the long run, especially if gas prices are only expected to be lower by a few cents.

You would only save:

$0.05 x $12 = $0.60

Saving 60 cents is nice, but driving an extra 10 to 15 miles to save money probably isn't worth your time.

Your best bet is to determine what time of the day is convenient for you to compare prices.

For instance, if your gas tank is a quarter full by Sunday and prices appear to stay constant, you'd probably want to wait until Monday.

However, if you have a long trip Sunday night, you'd want to fill up early.

How to Find the Cheapest Gas Near You

Instead of obsessing over what day of the week is the best to buy gas, you should look in your normal vicinity.

There are gas-price apps that allow you to search for the cheapest gas by city or ZIP code. GasBuddy has a similar feature that allows you to search for gas stations and filter them by cash only or offering a discount.

GASBUDDY HELP CENTER

You should look for the best prices of your own accord and not always rely on what's convenient.

There are many alternative shopping strategies that you might not be aware of, like:

• a Cash and Carry is cheaper
• a grocery store is cheaper and offers fuel discounts with a loyalty program
• stations farther away charge less

You can find all of these by doing a quick search.

You may also want to compare broader fuel-price trends in different markets. For example, ENG366 has a separate guide on gas prices in Toronto, which can help readers understand how location can affect what drivers pay.

Does Paying Cash Save Money at the Gas Pump?

Yes.

Cash is always cheaper than credit at the pump, but not everywhere. Some gas stations display both cash and credit prices to give an incentive to pay cash.

Consider rewards credit cards prior to purchasing something where the cash price is better.

For example, a credit card that earns a significant cash back reward on fuel purchases would likely result in an effective price that is as good as or better than the cash price.

Ultimately, you should analyze the final price.

Warehouse Clubs Might Be Worth a Look

Warehouse retailer members may receive a discounted gas price.

AAA mentions that in some cases, gas prices at warehouse stores are cheaper than at other stores, though you must factor in the cost of a membership and how frequently you buy gas to determine if it is worthwhile.

AAA CLUB ALLIANCE

If you have a membership, checking warehouse gas prices is worthwhile.

Just remember, it's never a good idea to drive far out of the way just to save a couple cents on gas.

If you're comparing different gas station brands, you may also find our guide on 7-Eleven gas prices useful.

Plan To Buy Gas Before Major Holiday Travel

Holiday travel will increase demand for gas, leading to congestion on the roads and higher gas prices.

If you are traveling a long distance, it's better to get gas before everyone else rather than waiting for Monday to get the "best" price.

You should keep an eye out for price reductions ahead of:

• Memorial Day
• Independence Day
• Labor Day
• Thanksgiving
• Christmas

Other price increases may cause Monday's "best" prices to quickly disappear.

Making Sure Your Vehicle Gets Better Fuel Economy

It's always better to use better fuel rather than just relying on buying the cheapest fuel.

Although using cheaper fuel may seem to save money, over time, it will cost you more if your vehicle has lower fuel economy.

According to AAA, keeping your tires properly inflated is the first step toward improved fuel economy.

AAA CLUB ALLIANCE

Other practices that improve fuel economy include:

• Accelerate smoothly
• Remove unnecessary heavy cargo
• Combine errands
• Follow the vehicle's maintenance schedule
• Use recommended gas

Proper inflation of your tires is critical not just to your fuel economy, but to overall performance and safety of your vehicle as well. Drivers will not save fuel by purchasing gas in search of the slight discount.

Do You Need Premium Gas?

The answer is almost always no.

Check owner's manual.

For vehicles that are not designed to take premium gas, purchasing premium can be a costly gamble. A substantial price difference also exists when looking at premium gas versus regular gas. The difference can be seen when looking at the U.S. Energy Information Administration data for regular, midgrade, and premium gas.

Best Gas-Buying Strategy for U.S. Drivers

Using a simple routine is better than relying on a strict rule.

Monitor prices on Mondays. Compare prices in your area when getting gas. Pay attention to prices near you before taking a big road trip. Use a gas rewards program only if it really benefits you. Don't go out of your way to save a few cents.

When doing all this, keep in mind that the overall price is what really matters.

Using your judgment, buying gas may be advantageous at a station that's only two minutes off your normal route if gas there is only $3.45, compared to the $3.39, unleaded gasoline down the road which requires you to drive an additional 15 minutes.

Convenience, fuel economy, time, and price are all factors.

If you're also interested in the business side of fuel retail, ENG366 has a detailed guide on how much profit a gas station makes per month .

Frequently Asked Questions

What is the best day of the week to buy gas?

The cost of gas is constantly changing based on a variety of factors but typically in the United States gas is cheapest on Mondays with Fridays being the next cheapest day. Comparing gas prices at local gas stations is always your best bet when you’re trying to save on gas.

AAA CLUB ALLIANCE

Is gas always cheaper on Monday?

No. Cheap gas is historically a trend that occurs on Mondays but oil prices and numerous other factors can cause prices to fluctuate and be cheaper or more expensive on any given day.

Is gas cheaper in the morning?

Temperature has no effect on the density of gasoline and there is no reason to believe that gas is cheaper in the morning.

Is it cheaper to buy gas with cash?

Cash and credit purchases both incur a cost on the part of the merchant. A gas station can set a lower price for a cash purchase but if the cash purchase comes with a discount then a credit card purchase should be made instead if the credit card offers rewards or cash back.

Should I fill my tank completely when gas prices are low?

Filling up your tank when gas prices are low is always a good idea as long as you have the means to use the gas. Rising gas prices are hard to predict.

Final Thoughts

So, what is the best day to buy gas?

Monday is the best bet for U.S. drivers, because of historical data. Friday can be good, too, in some cases. But neither of these are a sure bet.

To really save money at the pump, a combination of factors will have to be employed such as timing, price comparison, fuel rewards, optimal driving habits, good vehicle maintenance, strategic route selection and more.

Prices of gasoline change rapidly and can vary significantly in different locations. The folks who save the most money are seldom found following a strict rule of a single factor, like always buying gas on Monday. Rather, the best drivers are those who are flexible and selective in their buying behavior.

ENG366 desires to help drivers save money on each purchase by presenting data and analysis behind the variability of fuel pricing.