I've been reading these forums for a few weeks, but this thread got me to register and respond. I've been an ASE master tech now for over a decade and I know a bit about impact guns. A good tech will know how to use his tools and will use a torque stick with his gun when he zips up those lug nuts. You should be able to take them off again with a normal lug wrench if you need to do so. But: if the threads are worn or damaged, you will have problems no matter how the nuts are torqued. If you have a GMC 1500 or larger SUV with a 6 bolt wheel the threads manage to self destruct no matter how well you take care of them. Also, nearly all vehicles are designed to have either lubricated or non-lubricated stud/nut assemblies. Very few late model vehicles call for oil and can have problems if you add oil to the threads. Most older models require lubrication. The difference being what metals are used for the stud,nut, wheel, and mounting surface. If you live in a part of the country where corrosion is a problem, make sure the wheel is lubed where it contacts the drum/rotor/hub. Many times we have taken the nuts off of a wheel and then had to use a 5 lb hammer + dynamite + and act of congress to get the wheel unstuck from the corroded surface, not a good thing especially if you are not in a shop. Anyway, find a good tech to work on your car, that means you won't be getting work done at the sears or walmart by college kids. If you really must use a torque wrench to sleep at night, most wheels will torque at 90-120 ft. lbs. or if you only have a lug wrench, go about 12" down the handle and put half you weight on it (assuming you are around 200 lbs, more or less according to your size) when you torque the nuts in a star pattern.