Originally posted by: Triumph
Originally posted by: paulney
So I settled for a $22 version with a stupid tension rod and a scale. Looks like a POS, but whatever - I only needed to take off and put back on a couple of wheels.
I prefer the deflection style wrenches. They hold their calibration longer than a clicker type because they are a very simple device based on a 1st year engineering mechanics equation. And since steel can undergo an infinite number of cycles without ever losing its material properties (the numbers that plug into that equation), it'll stay accurate much longer than most clicker types.
"Accurate" in this sense means as accurate as a clicker wrench, because there's no real difference between 70 and 75 ft-lbs, for example. You can put a clicker on a calibration bench, do it 5 times, and get 5 different results across a range of probably 10 ft-lbs. Plus the method in which you use a torque wrench has a great effect on it. As someone else mentioned above, you need to do things like oil the threads, apply steady pressure, re-torque after setting, etc. Given all of these variables, there's no way that most clicker torque wrenches are going to give you +/- 1 ft-lbs of accuracy.
My lug nut spec is 87 ft-lbs. I put the deflection type torque wrench on them and turn them until the gauge hits about 90. Good enough.