I didn't realize just how many past threads and divided opinions on the topic there were.I thank everyone for your replies.
I've read enough folk swear by 3-in-1, WD-40, anti-seize, motor oil, white lithium grease, ATF and more. I'm convinced by the millions of miles you've driven.
I've learned a lot in the process. From what I can tell, I applied about as minimal lubrication as possible, and if anything, I might apply anti-seize next time. I will also wire-brush the inner threads.
Interestingly, someone on the Audi forums shared
a link and a page from their 2010 manual where Audi advised (10 years ago) to use anti-seize compound (Castrol Optimol). Not sure why they no longer include this advice in the work manual, but I think it shows what you've all been saying.
The manual states:
To install wheel bolts correctly, follow the sequence and instructions below.
Note - Do “not” use an impact wrench to install the wheel bolts.
♦ Before mounting a wheel, carefully clean all rim contact surfaces for the wheel hub, the wheel hub and the surfaces for the wheel bolts on the rim.
♦ Before installing the wheel bolts, carefully clean the thread and the cap contact surfaces.
♦ Apply the Optimol paste to the threads on the wheel bolts. Refer to the Parts Catalog.
♦ The ball bearing surfaces of the wheel bolts must be free of grease and clean.
♦ Do “not” use an impact screwdriver or impact wrench to insert the wheel bolts.
♦ Install all wheel bolts in a diagonal sequence until the wheel is seated securely on the wheel hub. Only then can the vehicle be placed on the ground.
♦ Place the vehicle on the ground.
♦ Use a wrench that is the correct size for the vehicle when tightening the wheel bolts to the specification.
♦ Set the required torque on the torque wrench.
♦ Tighten all wheel bolts in a diagonal sequence to the tightening specification when the vehicle is stationary on the ground.
♦ Check each wheel bolt with the torque wrench set to the correct torque at least once.
♦ By checking the torque, make sure “all” wheel bolts on “all” wheels are tightened to the required specification.
If all of the assembly steps were performed carefully and correctly, the wheel bolts do not need to be re-tightened after the vehicle has been driven a specific distance.