2006 Explorer 4.6 v8 has no power to tow up mountains?

BTW, this 4.6L 3V is 292 Hp and 300 lbs of torque, has a 6 speed trans (6R60) with a first gear of 4.17:1 and a 3.55 open rear differential. For 2009 and 2010, the torque went up to 315 lbs and used the same trans as the f150, the 6R80 which has a stronger torque converter.