Put the torque wrench at the three or nine o’clock position on a bolt that is real tight, then hang a weight on it and see what it reads. If you hang a 20 lb. weight 15 inches from the bolt’s center it should read around 24 lb. ft. of torque. I use an old beam and needle style torque wrench for my wheel nuts and it works fine. I think getting them close and consistent is more important than getting them to an exact value. If you get into cylinder head bolts you’ll want to invest in a better torque wrench.