Welcome to brain Stuff, a production of iHeart Radio, Hey brain Stuff Lauren Vogebaum here. Unfortunately for American drivers, gas prices often go up during the summer, starting around Memorial Day. There are many reasons behind the increase in summer fuel prices, and some are fairly logical. More people traveling, especially on
family vacations and road trips, increases demand. Also, in the spring months, energy companies conduct maintenance on their refineries, shutting them down and limiting capacity until late May, decreasing supply, and because of these disruptions, oil supplies can become stretched. In addition, natural disasters like hurricanes can increase prices by
disrupting transport routes and damaging refineries and other infrastructure. But did you know that the gasoline sold during the summer is actually different and more expensive to produce than that sold in the winter. Twice every year in the United States, the fuel supply changes. It's known as the seasonal gasoline transition. This change is the biggest reason for the price hike
in summer gasoline. Depending on the time of year, gas stations switch between providing summer grade fuel and winter grade fuel. This which started in nine as part of the Reformulated Gasoline Program, which was established through the nineteen ninety Clean
Air Act amendments. The Environmental Protection Agency or EPA, started the Reformulated Gasoline Program in order to reduce pollution and smog during the summer ozone season, which occurs from June first to September fift In order to reduce pollution, summer blend fuels use different oxygenates or fuel additives. These blends, the e p A says, burn cleaner and also help compensate for a limited oil supply. This practice of using
seasonal blends also encourages the development of alternative fuels. Remember that gasoline isn't just made up of processed crude oil. It's a blend of refined crude oil and different compounds and additives. The actual difference in cost of production varies, and it can add between five and fifteen cents per gallon to the cost of your fill up, depending on
where you live in the United States. No matter the difference in production costs, the increase at the pump is even greater owing to the summer driving season dips and supply maintenance costs, and companies converting to production of summer blends. The summer grade fuel burns cleaner than winter grade fuel. This means that it produces less small and releases fewer toxic air pollutants. During the summer, pollution is a frequent concern due to increased levels of smog and ozone, which
can harm the lungs. The summer heat boosts the formation of ozone, while the appearance of an inversion layer, which is an im mobile layer of air, can trap pollutants in the lower atmosphere. Summer grade fuel has a different read vapor pressure, or r VP than winter grade fuel, which contributes to its being marginally more eco friendly. R VP is the vapor pressure of gasoline measured at a
hundred degrees fahrenheit that's thirty eight celsius. The fuels with higher r VP evaporate more easily than those with lower r VP. A particular fuel blends r VP is based on the combined r VP of the ingredients that make up the blend. Irregulators worry about this evaporation because it contributes to ozone formation. The gasoline must have an r VP below fourteen point seven pounds per square inch or
p s I, which is normal atmospheric pressure. If a fuel's r VP were greater than that, excess pressure would build up in the gas tank and the fuel could boil and evaporate. Depending on where you are in the US, the e p A standards mandate and r VP below either nine point zero or seven point eight p s I four summer grade fuel. Some low regulations call for stricter standards, and because of these varying r VP standards, more than fourteen different types of fuel blends are sold
throughout the US during the summer. Because r VP standards are higher during the winter, winter grade fuel uses more buttane as an additive. With its high r VP of fifty two p s i. A winter grade gas has about ten percent butane in its blend. Butane is inexpensive and plentiful, contributing to lower prices. Summer grade fuel might still use butane, but in lower quantities around two percent of a blend. So when do companies start producing these different summer fuels. The e p A defines April to
June as the transition season for fuel production. Refineries switch over to summer blend production in March and April, and gas stations have by June one to switch to selling summer grade gas, while terminals and other facilities upstream from pumping stations have to switch by May one. Following summer driving season, companies switch back to winter blends beginning in September, with the first winter increase in r VP allowance occurring
on September. In a two tho one report, the e p A said that quote roughly seventy five million Americans breathe cleaner air today due to the seasonal fuel program. Still, the increased price, combined with the use of controversial additives like ethanol, which is less energy efficient than gasoline and produces more small, means that the program may still have its detractors. In times of crisis or natural disasters, the
e p A may waive the summer fuel mandates. Two recent examples were the ransomware attack that caused the Colonial Pipeline, which supplies gas to states all along the East Coast, to shut down, and the COVID nineteen pandemic. In In the former case, the waiver was to keep fuel prices from getting too high, and in the ladder, the drop off in gasoline demand meant that more time was needed to transition from winter to summer fuel. As gas storage
is limited. Today's episode is based on the article why is gas more expensive in the summer than in the winter on house to works dot com written by Jacob Silverman. Brain Stuff is production of Our Heart Radio in partnership with house toffworks dot Com and it's produced by Tyler Klang. Four more podcasts from My heart Radio, visit the heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.