John Waggoner

USA TODAY

Oil prices are weighing on global markets as crude prices continue sliding.

A barrel of the benchmark U.S. crude, West Texas Intermediate, sold for January delivery on the New York Mercantile Exchange is down to $57.99 in afternoon trading. The Dow Jones industrial average fell 195.48 points, or 1.11%, to 17,400.86.

Uncertainty over oil prices is weighing on markets, especially after the International Energy Agency said global oil demand in 2015 will grow by 900,000 barrels a day, 230,000 less than previously forecast, to 93.3 million.

Demand is growing more slowly despite lower prices for two reasons. The first is the economic slowdown in Russia, which is expected to slip into recession next year.

The Chinese economy, too, is sinking faster than its government would like. Chinese factory output growth declined to 7.2% in November from 7.7% growth in October. The data came after Chinese leaders at an annual planning meeting affirmed their commitment to the "new normal" of slower growth as they try to steer China toward a more sustainable expansion based on domestic consumption.

The second reason: Oil is priced in dollars, and the value of the dollar has been soaring in recent months. While oil has fallen precipitously in U.S. dollars, the dollar's gains have blunted those declines for people purchasing oil in euros or yen.

Britain's FTSE 100 sank 1.3%, while Germany's DAX fell 1.1%. France's CAC 40 declined 1.4%.

Oil stocks continued to get hammered. ExxonMobil, the nation's largest oil company, fell 1%, to 88.31. Oil services company Schlumberger (SLB) fell 2.02%, to 81.33. And Energy Select SPDR ETF fell 1.59%.

The fall in oil prices is good news for consumers, who haven't seen a decent raise in years. Gas prices peaked at $4.103 in 2011, and are down to $2.60 today, according to AAA. On a 15-gallon fill-up, that's a $22.55 savings. If you fill your tank once a week, that's $1,172 extra in your pocket.