Oil prices plummet more than $6 amid economic fear

Tuesday's sell-off alone is unlikely to bring drivers much relief.

"People shouldn't expect to see their pump prices drop," Kloza said. "By the end of the week, we may be talking about $4 (a gallon), we may be talking about $4.20. That's the nature of the beast."

General Motors Corp., the leading U.S. automaker, said it is assuming oil prices will hover between $130 to $150 a barrel next year. The company made the prediction as it laid out plans to slash jobs and truck production, suspend its dividend and borrow up to $3 billion as it grapples with an ailing U.S. economy and record high fuel prices.

In other Nymex trading, heating oil futures fell 14.59 cents to settle at $3.919 a gallon, while gasoline futures tumbled 17.29 cents to settle at $3.3848 a gallon. Natural gas dropped 48.2 cents to settle at $11.477 per 1,000 cubic feet.

In London, August Brent crude fell $5.17 to settle at $138.75 a barrel on the ICE Futures exchange.