I was wondering what was everyone's feeling on leaving your truck running when making short stops? I spend all day in my truck with a lot of 5min stops. I just take the remote with me and lock it up running. I will even leave it sitting the the home depot parking lot running while i run in to grab stuff. My question is, is this better for the truck or does it even matter? I know it sounds crazy but I left it running alot through a tank of gas a few times and actually got slightly better mileage than turning it off every time i went in somewhere( 18.9 as opposed to 18.0) alsoI notice that you guys post average mpgs at around 14 to16 per gal. Mine seems to get the same mileage not matter how or where I drive it. ( 17.9- 18.1) i lot better than my old tundra! ( piece of junk truck, especially fora toyota)

04 2500hd lb7 extra cab long bed 4wd stock:D my first diesel I love it!!!!

Been dicussed many a times before.....consensus is if the engine is up to temp you are better off shutting it down.

If I have just pulled a steep hill or something like that, I let it run.
But only if it will be sitting just a few minutes. Otherwise I cool the
turbo shut it down.
I have read pros and cons, and somewhere there is a study of
fleet trucks, and the long idling was determined to be bad.
Even the UPS man shuts down, just to come to your door and walk back to his
truck.
You might want to search the site for more info.

I know UPS has a rule that they have to turn the truck off at every delivery. Seems crazy to me that they can't lock it somehow to rule out someone jumping in and taking off. I bet they go through alot of starters. I always let mine run at rest areas and places where it will sit less than 5 or 10 minutes, especially after coming off the interstate. I know they say that this turbo doesn't run as hot as aircooled, but I don't want to risk coking oil in the turbo bearings.

I pull a very steep grade not 1/4 mile from my house every day on my way home.
I have a Pyro, and when I pull in the driveway and park, preturbo Egt is normally
around 450-500. Sitting parked with RPMs around 1200-1400, it takes less than a minute to see the EGT drop below 350.

Get a turbo timer of some sort, set it for two or three minutes and forget about it. ...........mine seems to burn as much @ idle as it does on the road?

The addiction of the power I believe is what drops alot of our mpg.
Depending on where you live and what time of year it is idleing for long periods of time without having a high idle can cause carbon build up and cause problems in time.
On the other hand in some states as mentioned on another post you can get a ticket if you leave your vehicle running for a certain amount of time.

For less than 10 mins. I would leave it running your going to do more damage shutting it off. IMO

As mentioned above if your towing a heavy load and have to stop right after the tow then let it idle for about 2-3 minutes,as for freeway driving it depends on after you get off the freeway, are you running it at slow speed for about 2-3 minutes or longer before you have to shut it off if so then shut it off and another way to look at it if it was a big problem with heat build up then it would say let them idle down in you owners manual, but it doesnt.

For short stops I leave it running with my remote starter, if I stop for awhile I just hit turbo cooldown setting on the remote. It runs for a minute, I try to shut it off under 300degs.

Thus why I miss the gauges on my cummins. I had them on my d=max and it was nice to watch the egt gauge drop before turning off the truck. Now I wait and wonder. Maybe someday they will have egt, boost, and tranny gauges standard on all diesel's.

Be careful.... In some cities it is Illegal to leave a vehicle running while unoccupied. It does not matter if it was locked or not.... They will ticket you.

L8r

Hence, the timmer.

jmpdmax is right..please check with your local law before leaving you truck idleing...in most of the states is against the law to leave any diesel motors idle for long periods,there's a article in shell rotellas web site on this issue.

Another option is to get a remote starter. They have a feature on them where you can just hit the remote start button while it's running and it will keep it running when you take the key out. This way you can lock it and if someone were to break in, it would shut off as soon as they touch the break. I know DEI and CODE remote starters have this, not too sure about the others.

I have a Valet, will run for 25 minutes on 1 setting or for 1 minute for turbo cool down in setting 2.