We’ve lost 4 diesel trucks this year to catastrophic failure. 2-22's and 2-24's. Two were due to excess idle, due to the nature of our construction work. Both idle trucks were close to being out of warranty as far as milage was concerned. GM denied the warranty as they were over the milage because they count every hour of idle time towards miles driven. I can't remember the exact number but something like 20-30 miles per hour idle. First time I have ever heard of this, but I guess it's a thing. Company bulletin went out the crews can idle in the winter to warm the truck up and clear the windows. Other than that trucks need to be turned off, even if they move the truck 50 times in a day. Starters and batteries are way cheaper than a motor replacement.