Split on whether to warm up a diesel before loading it or not

I've got a 6.0 Ford work truck I use for my landscaping gig. My old mechanic swore by idling it 10 minutes before hooking up the trailer, said the oil needs to circulate. Then a younger guy at the parts store told me I'm just wasting fuel and building carbon, said to drive it easy for the first mile instead. Tried both ways for the last 6 months. Truck seems fine either way honestly. Any of you guys run into this differently based on your climate or the engine?

2 comments

2 Comments

derek_ramirez1mo ago

Drove a 7.3 Powerstroke for 15 years in Minnesota winters. I'd let it idle five minutes tops on cold days to get the oil moving before I put any load on it. Anything past that and you're just burning $4 diesel for nothing. Summer time I just started it and went, took it easy on the first couple hills. Carbon buildup never gave me problems and the truck made it to 280k miles before I sold it.

janab821mo ago

@derek_ramirez pretty much nailed it with that five minute rule. I see the same pattern play out in a lot of things people overthink like warming up a truck or letting a lawnmower idle forever before cutting. It is almost always better to do what works for your specific situation than follow some old rule that might not apply anymore. Climate matters way more than people admit because running a cold diesel in Minnesota is not the same as doing it in Texas. My 6.0 has been fine with a short warm up and easy driving, and I figure the carbon buildup fear is mostly from people who never change their oil on time.