Why Do Gas Prices Go Up and Down?
Updated Nov 7, 2026
What you pay at the pump is crude oil, refining, distribution and taxes. Here is how each part moves the price, with today’s national averages.
The national average for regular is $4.069 a gallon today, and diesel is $6.231. Those numbers move almost every day, and they can differ by more than a dollar between states. Four things decide where they land.
1. Crude oil
Crude oil is usually the largest part of the price of a gallon, often around half. It is traded worldwide, so a production cut, a conflict in an oil region or a change in demand from big economies shows up at U.S. pumps within days or weeks. Prices tend to rise quickly when crude rises and fall more slowly when it drops.
2. Refining and the seasons
Refineries turn crude into gasoline and diesel. When a large refinery shuts down for maintenance, a fire or a hurricane on the Gulf Coast, supply in its region tightens and prices jump. In summer, federal rules require gasoline with a lower vapor pressure to limit smog; that "summer blend" costs more to make, which is one reason prices often climb in spring.
3. Distribution and the station itself
Pipelines, terminals and trucks add cost, and so does running the station. Stations near highways or in areas with little competition usually charge more, while warehouse clubs and big chains that sell a lot of fuel can price lower. That is why two stations a mile apart can be 20 or 30 cents apart. You can compare them on our gas prices near me page.
4. Taxes
The federal excise tax is 18.4 cents a gallon on gasoline and 24.4 cents on diesel, unchanged since 1993. Each state adds its own taxes and fees, and some also charge sales tax on fuel. California combines high taxes with its own cleaner-burning gasoline blend, which is why it is usually the most expensive state.
What this means for you
- Prices in your state follow crude oil with a delay, so a big drop in oil usually reaches the pump within a few weeks.
- Spring and early summer are often the most expensive time of year; late fall and winter are often cheaper.
- The biggest everyday saving is choosing the right station: compare before you fill up.
See how prices developed over the years on our gas price history page, or compare every state on the home page.