CHICAGO (CBS) — Drivers preparing to hit the road for the holidays were being greeted with a lovely Christmas gift this week: gas prices hovering at a five-year low.

“It’s a nice Christmas present for most of America,” said Phil Flynn, senior energy analyst at The PRICE Futures Group.

The Lundberg Survey found gas prices have plunged 25 cents per gallon nationwide over the past couple weeks, with prices under $2.50 a gallon at many Chicago gas stations. showed the national average at $2.37. In the Chicago area, the average price of regular unleaded was at $2.53 and falling on Monday.

Flynn said the plunging prices at the pump have been the result of sinking prices for crude oil.

“OPEC is trying to drive down energy prices by trying to increase production in a global economy, and over-producing more oil than there is demand; trying to flood the market with oil, driving down these prices,” he said.

Flynn said that’s the result of a price war being waged between the Organization of Petroleum Exporting Countries (OPEC) – especially Saudi Arabia – against American energy producers.

“This is about market share. This is about power. This is really a struggle for control of the global oil market,” he said.

Gas prices in the Chicago area ranged from a low of about $2 per gallon to nearly $4 per gallon at one station in the city.