[Lil bastard]

Air tools save time and make servicing your car more affordable. Wanna pay an extra 2-3 hrs. labor because someone disassembled/reassembled your car with hand tools? Even if you do, the shops don't - it's all about revenue per bay/hr. They need to maximize this and air tools help them do this.

That said, there are many types of air tools. An impact wrench is supposed to used only for removing stubborn fasteners. To attach a fastener, you are supposed to use an air ratchet wrench. Any torqueing s/b done by hand. There are breakaway torque sticks which use a sort of calibrated clutch to stop the force of the tool at a certain torque. These are very inaccurate, yet this is what many tire shops use. Also, they're made for use with an air ratchet wrench only. If you use them with an impact wrench (which uses pulses of air), the torque stick 'resets' between the pulses and so never releases the force of the tool.

Air tools are also at the mercy of the compressor and it's regulating valve. These are almost never recalibrated (though they s/b with great frequency, esp. in shop use).

Air tools are a good thing if used properly, but few shops do and even fewer do so consistently.

I have a full set of air tools and use them all the time - properly.

If you're going to farm out the work on your car, there are two things you should do. First, look around the shop and see how they're using their air tools. If the only thing you see being used is an impact wrench, pick another shop or assume the risk.

Also, when having work done, specify in writing on the service order that you do not want air tools or torque sticks used to tighten the fasteners. This way you have their agreement in writing before the work begins. Again, any shop unwilling to do this would be one to avoid, or as I said above, assume the risk.

Cheers!