If this is so, then why do all the mechanics in my shop agree that they are often highly inaccurate, and refuse to use them on their own cars? At the dealership I go to, many techs are the ones that are the first to say that these torque sticks are inaccurate. If you have never had a problem with them, you are either unbelievably lucky, or your customers haven't realised that some of their problems are due to this inaccurate tool.

VCNA is not the be all and end all or proper car maintenance. As any business, they must compromise here and there. It just so happens that VCNA considers this an acceptable risk.

Just think about the way this tool functions. By using an impact gun, running off a central system, the torque the impact gun provides, varies so greatly. Say a shop has 10 bays, each bay having one outlet for air tools, all running off one large compressor. You're telling me that each impact gun is going to receive the same amount of pressure when it is the only drain, compared to when all 10 bays are using pressure?

If you are happy using this on your car, and your customers, that's fine. But with them paying your dealership for service, they have the right to request the added accuracy of using a proper torque wrench. And yes, your dealership has the right to refuse, but then again, trust me, most Volvo dealerships, atleast in my area, have no problem whatsoever with this issue.