Vent: My old boss in Billings swore by a 30-minute warm-up for the big dozers in winter, but my new crew says 10 is fine.

Last week on a cold morning site, I did the full half-hour like I was taught, and the foreman joked I was wasting fuel. Three years ago in Montana, we had a Cat D6 seize up after a short warm-up, costing a full day's work. Do you guys stick to a set warm-up time, or just go by feel?