Re-checking wheel bolt torques

[rip]

This is not on my Elan but...

I have a separate set of wheels for my daily with winter tyres on.
I put these on recently & followed the usual procedure of tightening the nuts with my impact wrench then going round the torque wrench once all 4 wheels were back on the ground.
It is recommended that they are re-checked after about 50 miles & this is something I usually do even though I have never found any loose...until now.

The first nut I checked was so loose I was surprised it had not gone completely. The rest were ok on that wheel & the next 2. The last wheel had 3 (of 5) which were a little loose.
Did I finish tightening all of them with the torque wrench in the first place? I think so. I go round the entire car checking before I put my tools away, so I shouldn't forget 1 wheel or 1 bolt.
I am glad I re-checked them & will now make it an important point to re-check.
I checked again after a further 50 miles & they were all ok this time around.

[MPx]

I've had the same once on the Rangey Iain but can't offer an explanation. My routine differs very slightly to yours. I put each wheel on and tighten as far as I can, then lower the wheel to the ground but with only enough weight on it to stop the wheel spinning while I go round all five bolts with the torque wrench. I click round twice and count 1 to 5 as I'm doing it so confident I don't miss any. Only once that's finished do I fully lower and go on to the next wheel. What I noticed when it happened to me was a missing bolt! And then on checking them all another was also loose, and it was on the same wheel. Been doing the changeover, around each Winter season on two cars for more than a decade and only the once have had the problem.

[HJ2]

I always re-check (my procedure is similar to MPx)

I sometimes find loose bolts after 1 week, when i re-check (depending on how much i drove the car) However: I recon it is the number of heat cycles that is more important than the number of miles driven before re-check.
I found numerous loose bolts on numerous cars, but NEVER after a re-torque after oooh, say 4 - 5 heat cycles.