Since you have demonstrated the inability to research your position.
Gas Buddy Senior Petroleum Analyst Patrick Dehaan says competition between stations in the Great Lakes area leads to the continuing fluctuations.
“The markets are almost hyper competitive in these areas – gas stations continually undercut each other until they are both losing money and then one decides to raise prices very high to make up for that loss and then the other station matches – then they start going back and forth on prices going down,” he says.
Our analysis is the first, however, to detail when cycling started, mid-2000, and that it continues unabated. We find consumers are better off on average in cities after they began cycling. … This finding is consistent with the hypothesis that price cycling is a form of retail price war.”
http://www.journal-news.com/news/news/lower-gas-prices-predicted-for-2014/ncgQR/
Gregg Laskoski, senior petroleum analyst for GasBuddy.com, said gas prices in the region went up by 30 cents in a single day in 2013. In Fort Wayne, Ind., prices increased 34 cents in one day. Outside the region’s seven-state footprint, the largest one-day change was 14 cents, in Lubbock, Texas.
“You’re in a region where there’s more price volatility than anywhere in the country,” Laskoski said. “You see price jumps that are incredible. It’s created and perpetrated by the dominant retailers. They have huge spikes and come down. Once they hit the floor they go way up. It’s got to be extremely frustrating for consumers.”
Laskoski expects the trend to continue in the region. Last month, the U.S. average price for a gallon of gas floated within a 7-cent range. Cincinnati’s average price per gallon fluctuated by roughly 40 cents.
Jamal Kheiry, spokesman for Marathon Petroleum Corp., based in Findlay, said the price moves in the Midwest are influenced by many factors, including the price of crude oil.
“The retail gas market is extremely competitive,” he said. “You have different factors and costs and it could be any number of those factors.”
http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/gas-price2.htm
"Another area where prices have far exceeded the U.S. national average is the Midwest. In 1999, before the rest of the country started using ethanol-blended gas, the Midwest region became subject to rules that required the use of ethanol. Few refineries outside the region produced this type of reformulated gasoline, which meant that demand could outstrip supply. This was one of many factors contributing to higher gas prices in the Midwest in the early 2000s. The problem cropped up again across the United States after the national call for ethanol-blended gas in the spring of 2007.
Crude oil inventories have the single biggest effect on gas prices, and the United States depends heavily on foreign oil supplies. In July 2008, the United States imported about 13 million barrels of oil and petroleum products per day [source: EIA]. We'll look at exactly where that crude oil comes from next."
All alternative explanations other than a single supplier is gouging gasoline prices.