TAMPA BAY – Gas prices in Tampa Bay set a new record high of $3.565 a gallon on May 11, up more than a cent from the day before.
According to AAA Daily Fuel Gauge Report, the pump price for a gallon of unleaded was $3.656; mid-grade was $3.961; and premium $4.034. Diesel fuel rose a little more than 3 cents to a new record high of $4.284.
According to the federal Energy Information Administration’s This Week in Petroleum report, gas prices won’t be going down anytime soon. Most likely, they will continue to rise as refineries begin production of the more expensive-to-produce summer-grade gasoline.
The latest projections from the EIA show that the wholesale price for May will increase by 10 cents a gallon, inching closer to earlier predictions that gas prices could hit as much as $4 a gallon this summer.
May 1 marks the date when most areas of the United States require the use of summer-grade gasoline, the EIA said.
While the explanation of the differences between winter-grade and summer-grade gas is a bit complicated, the jest of it is that warm temperatures affect the evaporation of gasoline into the atmosphere, leading to increased health problems, more smog and increased levels of ozone.
The culprit is vapor pressure, and gasoline manufacturers and the U.S. Environmental Protection Agency walk a fine line trying to find the perfect mix that reduces the evaporation rate while still allowing for the more efficient operation of gasoline engines.
According to the EIA, the EPA first enforced vapor pressure regulations in 1989 with decreased vapor pressures allowed from May 1 to Sept. 15. The maximum allowable vapor pressure was lowered again in 1992. In 1995, the EPA introduced the reformulated gasoline program, which lowered the allowable levels of vapor pressure even more.
“Gasoline with lower vapor pressure is generally more expensive to produce,” the EIA said. “For example, one method refiners use to reduce vapor pressure is to reduce the volume of normal butane, a liquefied petroleum gas with high vapor pressure, that is blended into gasoline.”
Butane is a lower-cost component of gasoline. Removal of that component increases the production costs.
The national average price for a gallon of unleaded rose for the sixth week in a row, the EIA said. AAA’s Daily Fuel Gauge Report shows the national average at $3.707 on May 11, which was a new record. The nationwide price for diesel fuel also set a record on May 11 of $4.330.
