Sep 10, 2024 – There’s a bit of good news for the pocketbooks of drivers, as well as those across the country. Gas prices have started to fall and they can be expected to continue falling as we head into the fall and winter months.
On Sept. 15, gasoline refineries are to switch from making the more expensive, summer-blend gasoline and move to the cheaper, winter-blend gasoline.
According to the gas price monitoring service Gasbuddy, seasonal temperatures and government regulations make a big difference in the type of gasoline we use in our vehicles and the resulting price at the pump.
In the warmer months, gasoline has a greater chance of evaporating from your car’s fuel system. This can produce additional smog and increased emissions. Refiners reduce the possibility of gas evaporation in your vehicle during the summer by producing gasoline blends with lower Reid vapor pressure (RVP), or lower volatility. These blends vary from state to state and region to region due to RVP state regulations. They also vary by octane level.
The summer-blend gasoline can add up to 15 cents a gallon to the cost of your gas fill, a price that is added with another 5-15 cents a gallon due to summertime demand.
Come wintertime, blends have a higher Reid vapor pressure, meaning they evaporate more quickly and allow gasoline to ignite more easily to start your car in cold temperatures. This blend is cheaper to produce, resulting in lower gas prices at the pump from late September through late April. As they are cheaper to produce, gas prices can drop between 10-30 cents a gallon, starting in mid-to-late September and continuing through the end of November.
Many retailers continue to sell summer gas until their inventories run out before selling winter gasoline. Hurricane season can also affect prices, ending in a squeeze just before the switch as refiners don’t want excess expensive summer gasoline sitting around especially if refineries are in the path of a major storm.
The Environmental Protection Agency (EPA) requires fuel terminals to sell only summer gasoline on May 1, while gas stations have until June 1 to complete the changeover to summer gasoline. The switch from winter to summer gasoline is one of the major factors behind seasonal fuel price increases in May.
Meanwhile Sept. 15 is the last day that EPA requires summer gasoline, but most refiners start producing it again in late August and will draw down the remaining summer supply. In addition, gasoline demand falls as temperatures seasonally drop, leading gas prices to “fall” throughout the fall (a good way to remember it!). Starting Sept. 16, gas stations can start offering non-summer, or “winter” gasoline.
