found on the web... part of a lengthy thread about this subject... from someone who has actually tested the differences.

"bolts

What holds a bolt in place is stretch.... Think of the bolt as a spring, as you tighten it you stretch the spring.
The kind of lubricant that you put on any bolt will effect how much torque it takes to get the proper stretch. As you're turning that bolt in you have friction areas in the threads and where the bolt head contacts what ever you bolting together. So if you have dirty threads,dry threads, moly,oil etc... this will all change the amount of torque needed to pull a bolt up to a set amount of stretch.

I just spent about 10 hours doing some tests on rod bolts in my shop. You can take the same bolt and get totally different stretch depending on what kind of lube you put on the threads and under the head of the nut.When it come to rod bolts the only way to get the proper stretch is with a stretch gauge. If you are building a stock or close to stock motor you will be fine just using the factory specs for torque on factory bolts (i believe all the manuals recommend oil on the threads)

Try this simple test. Take a block of steel drill a hole through it and put a bolt and nut together thru it dry. Take a set of mic's and check the length of the bolt. Now start torquing the bolt in like 10 ft/lb increments. Check the length after every pull. Take it apart and put some molly lube on it and try again. Record the lengths per ft/lb dry and with molly you'll be surprised!!!! If you really want to get wild try it with different grade bolts...

keith

K-Star Automotive
Performance Engines"

i. as a pro mechanic, working on literally THOUSANDS of different machines thru the decades... always oiled the threads when the torque was critical... to NOT oil the threads could cause a FALSE TORQUE READING due to stiction.
the oil also reduces the chance of galled threads.
Special care MUST be taken when pre-lubing BLIND HOLE THREADS, or a hydraulic lock situation can occur.
i've watched one young trainee FILL the head bolt holes with oil once....the bolts would go in about two turns and Stop.
he got to sop up the oil with pa[per towels... i doubt he'll ever do the hole filling thing again..
if done to excess, in an aluminum casting, the hyd. forces can actually crack the structure around the blind hole... that would, thankfully, require more than two threads.

there are exactly ZERO "High torque fasteners" on bicycles. ZERO.
and grab-jump torquing of old corroded threads leads to totally worthless torque readouts.
rusty steering gooseneck wedges readily come to mind.
i saw one last year that had been OVER-tightened to the point of splitting the el-cheapo fork steerer tube.
i've also seen a draw bolt so badly rusted/galled up that it couldn't be snugged up enough to not twist in the steerer....

lube it or boob it, your choice.
and what stressed part of a bike always works better when the threads are lubed?
there's even "special lube" for those parts....

Spokes and nipples..

the most important thing is CONSISTENCY, not perfect achievement of some dreamed up "Safe Spec".
most CF parts fail to stay put when torqued to that "safe spec"... seat posts and bar clamps rapidly come to mind.
Conclusion: Engineers that Rarely, if Ever, work on anything, dream up what they think is a "Safe Spec" for a part, then the end users suffer the consequences, and some poor mechanic gets blamed when the bars slip on the first ride......
Signed: S. P. Mechanic, semi-retired.