[TimT]

and basically say that the 2 % error is 'good enough!'

OK ill just chime in and add a thought or two..

If you look in AASHTO, AISC, AWS and Im sure other acronymed manuals, You calibrate a torque wrench in a tension measuring device. The tensile strength of the bolt material is a known value, and the bolt recommended to be used for calibration is "lightly oiled".

Im sure all the auto manufacturers have standards they are required to follow that allow there product to be used on public roads. The SAE, TUV and propriatery specs would not call for dry threads... a lubricant of some sort is alway present to prevent galling of the mating surfaces

On lug nuts the application of anti-sieze should be conservative at best, this is an application where more isnt better.

BTW torque values for the bolts that hold together alot of the bridges we drive over?

7/8 bolt.... 600ft/lb to 900ft/lb torque

Porsche said that the 17" and larger wheels would not be hubcentric if the wheels were tightened on the ground

Ive seen lots of peeps do this, they rotate the wheels and snug up the nuts, then partially lower the car and final torque the bolts.