Diesel prices were up nearly 5 cents a gallon this week, to $3.868 per gallon nationwide, according to the Energy Department's weekly figures.
That's 93.7 cents per gallon higher than a year ago.

The highest prices were reported in California, where prices surged 10 cents to $4.058. It was followed by the New England region at $3.994 per gallon. Prices were $3.98 per gallon on the West Coast and in the Central Atlantic region. The lowest prices were reported in the Gulf Coast region at $3.80 average.

Crude oil futures were slightly lower Tuesday as investors acted on deepening concerns about the European and U.S. economic outlook. Light, sweet crude for October delivery settled down 43 cents, or 0.5%, to $86.02 a barrel on the New York Mercantile Exchange.

The price of West Texas Intermediate (WTI) crude oil settled at $86.45 per barrel on Friday, $1.08 above a week earlier. Compared with a year earlier, the price of WTI was up 15.9%.