My requirements is to show 15 minutes for a pre-trip, and we must flag a post trip while on duty. Supposedly, the system is set up to show a violation to safety if we don't show at least 15 minutes for our pre trip (elogs). I have tested that theory a couple times and never been told anything, but then again, they never tell me about any violation other than driving long distances while off duty
From the house, I will check tire pressure, fluid levels, check for signs of leaks, air test, check the lights, basically a thorough check. If a tire is low, it will get extra attention during the trip, and if it happens to be low again during the week, it will be fixed.
During the trip, I do a walkaround basically anytime I am out of the truck. During this time, I check lights, tires, and for any signs of fluid leaks. And yes, as long as the tires were good when I left the house, I just "bump" them during my walkarounds unless one appears to actually be deflated.