You got to watch those muffler and brake shops, too. Most of those places will ram the nuts on as tight as they'll go. I've had to replace many nuts/studs and even a few wheels because of that. James H and Hotrod Lincoln hit the nail on the head with how to properly torque lug nuts. I do prefer to get the manufacturers specs for torquing, but Hotrod Lincoln's spec list is perfect if you don't have acess to the specs. You would be surprized at just how high some newer vehicles actually torque to. Take the '98 and up Silverado for example. They torque to 140. Dodge Ram-135. And the f150-150. I just had an E250 in yesterday that torques to 170! Most passenger cars are right around the 100 ft/lbs mark, depending on make. GM is 100, most Chryslers are about 85-115, fords 87-105. Asian cars run anywhere from 75 (Toyota) to 87 (mazda) average.
We use those torque limiting extensions in our shop, and if used correctly, they do work. Of course we do recheck after anyway to be certain it's right. I personally use a digital torque wrench (Snap-On) that gives the actual reading, instead of just "clicking".
BTW-I work at a Sears, and have never broken a stud when installing a wheel. I have broken them taking them off, always after they had been serviced at one of the local brake shops or Wally World. And a few time when the Dealer had servived it, to.
