It's amazing how much chatter lugnuts can stir up.
;-)

So I have another question, regarding proper wheel tightening technique. I had an alarming event a couple weeks ago when my recently-changed spare wheel came loose while driving - maybe 100 miles after I had put it on.  (I heard rumbling from the wheel area that made me think of a failed wheel bearing. I pulled over to find front lug bolts backed out by 1/8 inch ). It made me wonder how that could have happened (and how to stop it in the future.)

I'm soon swapping the original steelies and dry-rotted Vancos with some Hankooks mounted on 14" Carat alloys. Mounting with the T3 lugs.

Typically, I take my car to a tire shop, but I wanted to try this myself. I have bottle jack, jackstands, a newly cleaned and organized garage, and a hammer drill. (It's an old electric beast, with a 5-setting clutch and a pretty good amount of torque). 

The tire loosening incident has me a little spooked.  I thought I did it correctly - put tire on wheel and tighten lugnuts as much as possible, working in a crosswise sequence.I put the car down on the ground for the final tightening sequence. (I was using stock lugwrench.)  How does that come to be rumbly loose 100 miles later?

Should I use the hammer drill (after proper threading)?  A torque wrench? (which I don't own, but would be pretty happy to acquire). Any treatment to the bolts/nuts?  Advisable period for reinspection?

Any insight appreciated.
Peter