Many consumers have been caught unprepared by the latest changes in the economy, especially the price of fuel.

The cost of crude oil set a new trading record of $111.80 a barrel on Monday. Prices fell sharply during the week, dropping to $101.84 a barrel on the New York Mercantile Exchange on Thursday.

The national average price for a gallon of diesel rose to a record of $4.03 a gallon Thursday.

DRC/Gary Payne

Gas and diesel prices at the Love’s Travel Stop at Interstate 35 and Milam Road near Sanger are shown on a sign March 20.

In Denton, flashing signs began displaying the record-breaking price per gallon for diesel. Gas prices followed oil to a number of recent records but have retreated slightly over the past several days as oil has wavered.

“Living with a high gas price is just a fact of life,” said Marie Montgomery, a spokeswoman for AAA Texas in Houston. “Some Texas cities have broken records and others have not.”

This week, automobile association officials reported the average price of regular gasoline in the Dallas-Fort Worth region as well as around the state at $3.18. Yet in other places such as Amarillo or Texarkana, prices continue to fluctuate by small amounts.

“Amarillo is 14 cents away from the set record of $3.17, Texarkana is currently $3.13; it went as high as $3.18 last week,” Montgomery said. “It can change in a week.”

Hillary Kamen, who’s used to gas price fluctuations as manager of the Shell station on McCormick Street, said this time around customers have been adapting.

“People are still buying the same amount,” Kamen said. “They are complaining more, though.”

She had noticed that regular fuel prices at her station went down twice in the past week. Starting at $3.15 per gallon for regular unleaded gasoline, the price dropped to $3.13 and then to $3.08 by Tuesday — the same day diesel hit the $4 per gallon mark.

According to FortWorthGasPrices

.com, a Web site that tracks prices in the Denton area, a Conoco gas station on University Drive had reached $3.29 per gallon by midweek.

Diesel followed oil’s recent surge but also faces a different demand dynamic. While U.S. demand for oil and gasoline is tepid, diesel is more tied to the global economy, where demand is growing.

The Love’s Travel Stop on Interstate 35 and Milam Road reported it recently increased its price of diesel to $4 per gallon.

“That is the credit price,” said Ryan Verdin, a gas station worker with Love’s. “The cash price is $3.98.”

He said he wasn’t sure whether the price would change over the next few days.

“We are getting the message from corporate,” he said. “We do what they tell us.”

Kamen said the price change is forcing people to put certain activities on the back burner, such as going to the movies or dining out.

The price increase affects each person differently, especially commuters who may be caught off guard by the increase, Montgomery said.

“It depends on your personal financial situation,” she said. “People average 10,000 to 15,000 miles per year. Once you get over that, it hurts you.”

Companies are feeling the pinch as well.

Three weeks ago, Bobby Massachio, general manager for Syracuse Sausage in Ponder, decided to switch one of the company’s three diesel-powered bobtail trucks to vegetable oil-based fuel.

Massachio said he learned how another company had benefited from the switch and decided to test it.

“It will be about $1.20 to $1.30 cheaper per gallon,” said Lance Morrison, transportation supervisor for Syracuse Sausage.

Since the company’s trucks travel weekly to supermarkets such as Kroger, Tom Thumb, Brookshire’s, Randall’s stores in Houston and others to deliver products, officials thought saving a little would not be a bad idea.

“The truck starts up on diesel; then switches to vegetable oil to run,” Michael Haynes, a manager with the company, said in an e-mail earlier this week.

Other local companies, such as car dealerships, are just adapting to the price fluctuation.

William Stalik, general sales manager of McNatt Honda in Denton, has seen many of his customers come in wanting to exchange sport utility vehicles for more economical and fuel-efficient vehicles.

“It is a Catch-22,” he said, citing the law of supply and demand.

“You have customers that have bigger vehicles like a minivan or SUV and they are trying to get out of that vehicle. But at the same time, so is everyone else,” he said. “So the value of their vehicle is going to decline.”

Manufacturers such as Honda and Toyota have put programs in place for customers wanting to take advantage of competitive interest rates and finance programs during a difficult economic time, he said.

“Their fuel expense now is as much as their car payment,” Stalik said.

He suggested people interested in trading their current vehicles do research and contact dealerships to see what deals they have, instead of going directly to their bank.

“If nothing else, at least they have a good understanding on what they could do,” he said.

The Associated Press contributed to this story.

KARINA RAMÍREZ can be reached at 940-566-6878. Her e-mail address is kramirez@dentonrc.com.