I own a store and I see nuts that are too tight all the time. Some cannot be removed with an impact wrench without breaking them. So… I think a lot of people squeeze them too tightly. I don’t believe the industry standard is 100 lb-ft. That is. Most owner’s manuals say between 70 and 90 lb-ft. it’s the right couple. What I do is put a wheel bolt in my vise with a nut, and tighten it with what I think is right, then check it with my torque wrench. This will teach you very quickly how wrong you can go wrong with a hook lock. Set a torque wrench to 100 ft-lbs and tighten a bolt to it. Now try to break it with a hook wrench. This will teach you again how wrong you can be. I don’t think most women can tighten a nut to 100 lb-ft. with the pin wrench that came with the car, let alone remove one. It can become a joke if we think about it enough.
The best thing to do is; follow what’s in the owner’s manual, apply anti-seize to the terminals and tighten them evenly in a crisscross pattern, and don’t give that extra tug at the end for good measure, because that’s what breaks the screws. Just remember; a woman may have to get rid of these horns one day so she doesn’t squeeze them so tightly, they don’t need them.
Part 2:
The year and make of a vehicle has nothing to do with torque. Which is; is the screw itself. I know all bolts have a symbol that indicates how much torque they can handle, but not the nuts. Almost every vehicle has a different torque number in the owner’s manual. I think they should give a maximum and minimum specification. Torque is based on the amount of stretch a bolt encounters in a force X applied to tighten it, so in reality each pin must be replaced each time they are removed, or the torque can be deflected by a large margin of nut to nut ear. No one will, but cleaning the threads and adding an anti-seize agent can be the difference between a warped rotor or a broken nut. A good rule of thumb to follow is; If it is not possible to operate the nut completely by hand, the specifications are off when torque is applied. Oh.. so you have the rust factor. Tighten them to no less than 70 lb-ft. and there should be no problem as long as they are in good condition and tightened in a pattern that exerts equal pressure from side to side.
Glad to help, good luck!!!