"MrCheerful" wrote:

I think not - but I've heard people say use the shortest extension bar you
can get your hands on. I don't understand why. It should be the same torque
if I used a 16-inch extension bar, right?


no because some force will just be twisting the bar, Imagine a bar a
mile long, you twist one end with a known force, the other end would not
move.

Oh crap. Is this myth still floating around?
We're not measuring *movement*, we're measuring *torque*.
Place a 100 pound weight on one end of a 5-foot long teeter-totter.
How much weight do you add to the other end to balance it?
Place a 100 pound weight on one end of a mile long teeter-totter.
Same question. (PS: You'll get the same answer)

Back to the actual question:
3-inch extension keeps you close to the nut, unlikely to twist sideways and fall off.
16-inch extension has the possibility of pulling the socket out of alignment, maybe
rounding off the nut, and scraping your knuckles (and your shiny new wrench) on the
ground, UNLESS you properly support the wrench at the head end to keep it straight.