NEW YORK - As consumers began hitting the road for the Memorial Day weekend, they faced the sobering reality that it now costs $87 to fill a Ford Explorer SUV, up $14 from last year, and $72 to fill a mid-sized Honda Accord, up $12.

That's because gas prices, which took another jump higher overnight, are up about 20 percent, or 68 cents a gallon, over the past year to average more than $3.91 a gallon nationally as of Saturday morning. But unlike this time last year, when gas prices were at their peak for 2007, pump prices now show no signs of halting their daily assault on the record books.

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"Four dollars (a gallon) is a done deal now," said Jim Ritterbusch, president of energy consultancy Ritterbusch and Associates in Galena, Ill. "We could go significantly above that."

Northbound traffic on Highway 371 on Friday afternoon was two wide and bumper to bumper from the Highway 210 and 371 intersection to the intersection of College Drive.

» Purchase reprints of this photo.Brainerd Dispatch/Clint Wood

On average, drivers in Alaska, Connecticut, California, New York and Illinois are already paying more than $4 for gas, and an increasing number of stations around the country are posting prices higher than $4. In Alaska, where the average price of regular gas stood at a national high of $4.177 Saturday, it now costs $94 to fill an Explorer and $77 to fill an Accord. The average in Minnesota was $3.832.

Nationally, the price of a gallon of regular gas rose about 3 cents overnight to a record average of $3.911 Saturday, according to AAA and the Oil Price Information Service. Prices are headed even higher in coming days because of oil's dramatic rally this week to a new record over $135 a barrel.

"We're going to see some more significant increases here in light of what we've seen in the last few days," said Tom Kloza, publisher and chief oil analyst at the Oil Price Information Service in Wall, N.J.

Oil prices fluctuated Friday after as investors placed bets before the long holiday weekend. Light, sweet crude for July delivery rose $1.38 to settle at $132.19 a barrel on the New York Mercantile Exchange, after alternating between gains and losses.

Supporting prices was the dollar, which weakened against the euro and attracted more investment money to energy futures. A growing number of investors have come to view commodities such as oil as a hedge against inflation and a falling dollar. Also, a weaker greenback makes oil futures less expensive to investors dealing in other currencies. Many analysts see the dollar's protracted decline as one of the chief reasons oil prices have doubled over the past year.

Northbound traffic on Highway 371 on Friday afternoon was two wide and bumper to bumper from the Highway 210 and 371 intersection to the intersection of College Drive.

» Purchase reprints of this photo.

Brainerd Dispatch/Clint Wood

Growing demand for fuel is also helping boost oil prices. Demand for diesel has spiked in China, where power plants in some areas are running short of coal after last week's earthquake. But even before the quake, Chinese diesel imports were rising sharply. China's government has released nearly 170,000 barrels of fuel from its strategic petroleum reserve this week to ensure adequate supplies in earthquake areas.

"China's just hungry for diesel," Ritterbusch said.

Diesel prices in the U.S. rose more than 5 cents to a record national average of $4.709 Saturday, according to AAA and the Oil Price Information Service. Diesel's rise has been far more dramatic than gasoline's; diesel prices are nearly $1.80 a gallon higher than a year ago. Diesel prices are averaging more than $5 a gallon in some parts of the U.S., and may rise above an average of $5 in California and New York state over the weekend, Kloza said. Diesel is used to fuel most industrial vehicles, and is a big part of the reason prices for food and consumer goods are rising.

Heating oil, which is closely related to diesel and often traded as a proxy for the fuel, rose above $4 a gallon on the Nymex on Thursday for the first time. On Friday, June heating oil futures fell 8.87 cents to settle at $3.8656 a gallon. Analysts cited profit-taking for the price swoon, but expect heating oil futures to resume their upward course next week.

Oil prices did come under some pressure Friday as some investors collected profits ahead of the weekend. Many analysts argue that oil prices have risen well beyond levels that can be justified by supply and demand fundamentals; an increasing number of analysts are referring to the situation as a bubble. U.S. demand for fuel and oil has fallen this year. Some analysts see signs in a recent switch in the relationship between the price of the current July crude contract and prices of crude for delivery in future months that tell them prices could soon fall.

Analysts also say a significant reduction in demand for gasoline could bring prices down. Energy Department data shows gasoline demand has fallen for much of the year, and new Federal Highway Administration data shows the number of miles Americans traveled fell 4.3 percent in March compared to the previous year - the first year-over-year drop in March travel since 1979.

But few analysts are willing to call an end to oil's rally, noting that investors just continue to plow money into the market, pushing prices ever higher.

"Big mo (momentum) is driving this thing now," Kloza said.

In other Nymex trading Friday, June gasoline futures rose 6.63 cents to settle at $3.396 a gallon, and June natural gas futures rose 16 cents to settle at $11.857 per 1,000 cubic feet.

In London, July Brent crude futures rose $1.06 to settle at $131.57 on the ICE Futures exchange.