Here, we got some pretty good mechs. Most will really work with you if you don't go over board.
Exam: When we had white Penske truck, in about Oct, we asked Penske guys if maybe we could have some new drive tires for before winter. We drove Il, WI, CO, all of midwest, had some pretty crappy winters. They responded, "They are all at least 3/32 and well within DOT guidelines". YEah, but are they gonna be in Feb and Mar in a snowstorm in WI?
Now in brown mileage truck, I asked assigned mech about drive tires...gettin pretty nasty, although within legal limits. He said, "No, problem. Next PMI". It helps that he's a cover driver too during summer and peak. HAH
By coincidence, two of our slackest supes came from mech. They were slugs when hourly mechs and are worse slugs now.