US stocks are closing mostly higher as the energy sector got some help from an increase in oil prices. ConocoPhillips jumped 4% Tuesday, while Pioneer Natural Resources climbed 8%. Several stocks were moving on earnings news. Trucking company Ryder System rose 6% after reporting results that were better than analysts had expected. Chemicals maker DuPont rose 2%. Appliance maker Whirlpool sank 4% after saying its results were hurt by a stronger dollar. The Dow Jones industrial average added 13 points, or 0.1%, to 17,990. The Standard & Poor's 500 index edged up three points, or 0.2%, to 2,091. The Nasdaq composite slipped seven points, or 0.2%, to 4,888. (More Dow Jones stories.)