These days, it’s the math that’s killing Mike Liu.

In an average week, the D.P. Dough delivery man spends $120 to fill up his 2005 Nissan Altima. On a good day, he makes $100 in tips. He works part-time.

Now, he’s thinking, with gas prices soaring above $3 per gallon, it might be time to switch rides.

“I really started taking a hit during this summer” Liu said. “ I put in $20 and all I got was enough for 6 gallons — that’s not even half a tank!”

Local businesses are now feeling the repercussions of ballooning gas prices forced skyward most recently by Hurricane Katrina, which tore through the Gulf of Mexico earlier this week, shutting down oil refineries and cutting daily domestic oil production by about one third, according to U.S. Energy Department analysts.

In the College Park area,consumers currently spend an average of $3.10 per gallon of gas. The average driver will also spend $38.63 per week to fill their tank compared to this time last year when it was $28.25, according to the AAA website.

With the Gulf producing roughly a quarter of the oil for the United States, it is estimated that 1.4 million barrels of oil are being lost each day because of the damage.

Papa John’s Pizza manager Ulises Visencio said he has seen his delivery crew drop from 14 to 11 drivers this summer because of the price hike.

“I hear their concerns daily,” Visencio said. “My drivers just can’t afford to constantly fill their tanks.”

As a delivery driver for the pizza company, Valerio Martinez said he seriously contemplated quitting his job after gas prices rose to $3.29 per gallon recently.

“I used to make $100 in tips a day,” he said. “When I saw the gas price was $3.29 the first [thing] I thought was I’m not going to make any money doing this job.”

College Park business owners said although they haven’t experienced any drastic problems, their distributors have started adding a fuel charge to the bill. That cost, however, hasn’t been passed on to students yet, owners said.

“On average, we get about 15 deliveries a week,” said College Perk Coffeeshop owner Chris Gordon. “Just recently, some of them have started adding $2 onto the bill to help cover their fuel costs.”

Number 1 Liquors owner Anuj Kapur said that one of his distributors has started adding the charge.

“I don’t anticipate my business really being affected by the gas prices right now,” he said.

If the gas prices persist at current levels, or shoot up even further, experts say prices charged to businesses could trickle down to consumers.

Economics professor Jonah Gelbach said the rising gas prices could take a toll on people’s disposable income, leaving them with less money to go out and spend.

“You could expect gas prices to cause some type of stress on a person’s finances,” Gelbach said. “If prices continue to rise, there will be an impact.”

Business and economic experts say costs could continue to rise as the effects of Hurricane Katrina on Gulf Coast oil refineries are assessed.

Visencio said many of his drivers are finding people have stopped tipping on orders, assuming the pizza company will pay for drivers’ gas.

“People don’t realize that our drivers pay for their own gas,” he said. “As of right now, an average employee spends about $35 a week filling their cars.”

To compensate for the higher prices, Papa John’s has started offering delivery drivers a 5 percent commission per order as an incentive.

Gelbach said major effects will really be seen if gas prices reach $5 per gallon.

Todd Stewart, owner of Vertigo Books, said when his store ships out books, the cost has gone up, and the publishing companies mostly pay for their deliveries each week.

“We have noticed a change in when we ship things out,” Stewart said. “It’s funny, even if the price goes down, the fuel charge would still remain the same.”

Overall, Visencio doesn’t believe things will get better any time soon.

“Things have been bad for a while,” he said. “It’s been a struggle trying to get drivers to fill the vacancies.”

Contact reporter Sara Blumberg at blumbergdbk@gmail.com.