Diesel Rockets Past $4 Mark

Diesel prices soared 10.2 cents last week to a national average of $4.078 per gallon, according to the U.S. Energy Information Administration.

As the retail price climbed for the 18th time in the last 19 weeks, it was the first time diesel rose above $4 since September 2008. Every region in the country felt the impact.

By The Numbers: U.S. Diesel Prices

Disruptions to the supply chain remained the chief cause of the prolonged increase that began in early December and has been spurred by revolts in Tunisia, Egypt, Libya and other Middle Eastern countries.

Unrest and confrontation in Libya have withheld from the market significant volumes of light, sweet crude oil, which lends itself to the production of light products such as diesel and jet fuel, EIA said in its mid-week summary Wednesday.

In the Rocky Mountains, where prices rose least, diesel climbed eight cents to $4.097 per gallon. The lowest prices were in the Gulf Coast, where diesel rose 9.6 cents to $4.001 per gallon. The Midwest saw the largest increase as diesel soared 10.8 cents to $4.04 per gallon. Diesel increased 9.9 cents on the West Coast to $4.308 per gallon. As usual, the West Coast price was inflated by California's average price, which ballooned to $4.397 per gallon last week, up 7.4 cents from the previous week.

-- Contact Thomas L. Gallagher at tgallagher@joc.com. Follow him on Twitter @TLGjoc.