My dad owns a lawn mowing business and tows with his 05 cummins. The jobs take 20-35 minutes, should he leave the truck run or shut it off. Keep in mind it is summer when he's doing this.
thanks for the replies. my dad is just worried that it never gets warm with all the short trips between the jobs.
It won't hurt to leave it running, but it also wouldn't hurt to shut it off. If it were me I would go for a couple of tanks leaving it running and take an average of the mileage and then figure out the average mileage when shutting it off during jobs... see what kind of difference it makes.
Shut it down. In the middle of the summer its not going to cool off real fast like in the winter. I can't actually tell you how much, but I know my milage drops quite a bit if I let my truck idle a lot. At $4 fuel, I try not let that happen much.
Cummins says not to let them idel more than about 10 minutes. when I had the Ford International said the same.
Maybe look into a turbo timer. That way if it cools down enough, it shuts down. If it doesn't then it will still be running.
with the price of fuel there is not much point in long idel times. the block heater if a 120v outlet is available would keep the block warm.
My understanding is that you don't want to idle for periods of time. I agree with everyone else, shut it down. If I do need to leave mine running, I use the high idle feature and bump it up to 1200 rpm.
