Bloomberg A polar blast that’s poised to sweep the US has turned natural gas into the year’s best performer among major commodities. Frigid weather will sweep the western two-thirds of the nation in the second week of January, stoking gas demand for heating, according to Commodity Weather Group LLC. The deep freeze comes as output from shale basins slows, …

  Bloomberg Hyundai Motor Co. and Kia Motors Corp., South Korea’s largest automakers, forecast sales to climb 4.7 percent this year as they count on new model introductions to counter intensifying competition amid global uncertainties. Hyundai and Kia are targeting to deliver a combined 8.25 million vehicles in 2017 from 7.88 million units a year earlier, according to regulatory filings. …

  Bloomberg South Korea banned the sale of 10 models built by Nissan Motor Co., BMW AG and Volkswagen AG’s Porsche after an investi- gation found the automakers fabricated documents related to emission tests. The three manufacturers were slapped with total fines of 7.17 billion won ($5.9 million), which apply to 4,523 vehicles, and the certifications given for these models …