How can grease lead to over-torquing? If you are using a torque wrench, one would torque to the same value, lube or not.
IMO you make the mistake of failing to recognize that the underlying and ultimately critical objective of a fastener torque specification is to achieve an intended design
tension on the fastener itself. It is tension on the fastener that dictates the actual performance of the assembly (along with friction of all of the assembly interfaces in consideration of certain loading conditions such as shear).
Fastener torque, when measured under proper conditions (i.e. CLEAN AND DRY unless otherwise specifically directed), is a good and well-established
surrogate (proxy indicator) for the actual tension imposed on the fastener; a surrogate that's useful and necessary in the actual practice of assembling components because there is no practical tool for
directly measuring actual fastener tension in the real-world setting of component assembly (though measurement of fastener tension is certainly practical in the laboratory setting).
For any given torque-wrench reading (the value of the surrogate) the
actual tension imposed on the fastener will differ between lubricated and dry conditions. It is in that critically important sense that the torque value can be rendered "false" - that is to say that the torque value expressed on the measurement device (the torque wrench) is no longer a "true" ("valid", if you prefer) surrogate expression for the tension imposed on the fastener. Again, it is the
actual tension on the fastener that dictates the stresses on the assembly, on the fastener itself, and thereby the actual performance of the assembly.
The long and well-established standard for fastener torque specifications is based on CLEAN AND DRY fasteners (unless specifically and explicitly stated otherwise); that's the condition that yields the
intended fastener tension, the the underlying critical performance factor for the assembly. The surrogate is not 'perfect', but the imperfect correlation between a properly measured fastener torque value and the actual tension imposed on the fastener of interest is well-established and considered in the derivation of those fastener torque specifications.
So yes, it may be more accurate to say that lubricating a fastener can yield "over-tensioning of the fastener" rather than saying it yields "over-torqueing" as expressed on the torque-wrench. But regardless of the semantics the point is that lubrication (or anything other than CLEAN AND DRY) can lead to imposing stresses on the assembly that it is not intended to manage and failure of the assembly to perform as intended. And those are potentially property and life-endangering conditions when it comes to road-wheels.
;D
