I am an engineering student at the University of Minnesota Duluth. Recently myself and others designed a devise to test torque output of a cordless drill. Due to time limitations we only had chance to test three different brands and three different battery sizes. I had no preference before this experiment. We chose to test the Dewalt 14.4v, 12v, and the 24v. We also tested the Makita 14.4 and 12v, along with the Craftsman 12v, 14.4v, and 24v.
Our results were very interesting. The 12v Dewalt puts out more torque than the other 12v, and more than any of the 14.4v, including the Dewalt 14.4v. The other more interesting thing that we found was that the 24v Dewalt puts out exactly as much torque as it advertises, 550 in/lbs. The Craftsman 24 advertises 625 in/lbs of torque, but only produces 540 in/lbs.
The next drill I buy, will be a DeWalt. I also learned not to trust advertised torque ratings. People should not assume that just because a drill has a larger battery, does not mean that it puts out more torque.