The closing price of $43.67 is a four-year low. Crude oil prices have dropped $27 in a single month, and have fallen more than $100 from a record high of $147 hit this summer.
The average price of a gallon of diesel is down to $2.722, according to the AAA Daily Fuel Gauge Report, compiled by the Oil Price Information Service in cooperation with Wright Express.
You can probably expect oil prices to stay fairly low -- although perhaps not this low -- through much of next year, predicted Kevin Lindemer of Global insight's energy practice in a webinar earlier this week sponsored by GE Fleet Services.
"We expect them to stay below the $60, $65 dollar range for at least the next few quarters," he said. "OPEC is just not going to be able to cut production back far enough in order to put the price back above this range."