It’s going to cost slightly more to fill up your vehicle this weekend. The statewide average price of gas is $3.15 a gallon this morning. That’s less than a penny more than last Friday. AAA spokeswoman Stephanie Dembowski says a slow increase in the price of crude oil is one of the reasons.

“The stronger economy, both domestically and overseas, has put some upward pressure on the price of oil and that’s really caused pump prices to just kind of stay where they are right now,” Dembowski said.

She says AAA expects gas prices to hold mainly steady, shifting up or down by a penny or two, in either direction, through the end of the year. Flagstaff continues to have the highest average prices in Arizona, at $3.35, while Tucson drivers are paying the least, at $3.07 a gallon.