I have about 750 miles on my truck now and this is my first personal vehicle that is diesel powered. I leave the truck idle alot when I'm in and out of different places. Mainly short trips right now only one 200 mile trip on it, my best fuel milage is 14 mpg. hand calculated average is 13.8 mpg. Is it this low because of the idle time, or is it just that the LLY is hard on fuel? I never let it idle longer than a half an hour, I have always been told it is better to let a diesel idle instead of constantly restarting it, this has been with trucks and tractors at work, from my dad who is an equipment mechanic, and my cousin who is a truck mechanic. Is all this idle time killing my milage or is this what everyone else is getting? Hour meter is up to 50 hrs.


edit: just double checked 744 miles 36.4 hrs. got confused trip meter is at 50 currentlyEdited by: TurboBeagleBuggy

Wow!!!!!!!!! Thats a lot hours for 750 miles!!!!!!


Your mileage is not that far off from my mileage, I am doing a bit better I think because I don't do that idle thing, don't want anyone to jump in and split with ithttp://www.dieselplace.com/forum/smileys/smiley36.gif. All the new Diesels are not doing well on mileage, its not just the LLY. My friends have Dodges and fords and we are all complaining!


DanEdited by: dwrat

That is a lot of hours for 750 miles with a 200 mile trip. If you idle that much you might want to think about installing a high idle kit.

your mileage should get better as you get more miles on the truck and
it gets worked in, mine started lower than it is now and seems to keep
getting slightly better, still only have 9k on it. Im getting in
the 14'ish around town and 18-20 on the freeway, so im pretty happy all
in all - all hand calculated every tank. I also let it idle quite
a bit as well, atleast 5 minutes before i drive it when its been
sitting for more than a couple of hourse, and if im running in
somewhere, same thing here, let it idle as ive pretty much heard the
same in regards to its better to idle than constantly restarting

Hey Beagle , that sounds about normal for that many miles. Might get to towing before to long with it and that will get her loosened up abit and help! I had a buddy with a Lund Visor and it hurt is mileage by about 1mpg !!

Not sure about a half hour idle time. I would say that if you are going to idle more than 5 or 10 minutes, go ahead and shut it off. . . If just for a few minutes, i.e. running inside to get something the wife forgot, or picking up another six pack, or delivering something, getting fuel, etc. . . leave it run, otherwise shut 'er down.


JMO,
Dennis

Idle time will hurt your fuel MPG's think of it this way, as your truck is sitting there running you are getting 0 miles to the gallon, that brings your average down pretty quickly

That is a lot of hours for 750 miles with a 200 mile trip. If you idle that much you might want to think about installing a high idle kit.


I have to agree with Ozzy on this, if you are idling a Diesel motor that much you should install a high idle kit. Diesels are prone to a condition called "wet stacking" I remember this from our generators in the Army, if they don't have a load on them they can wash down the cylinder walls with fuel as a Diesel motor at idle does not run hot enough to burn all the fuel. Not sure but this could also contribute to poor overall fuel mileage.


There is a thread on this forum about enabling high idle on the LLY's, might want to read this and add it to your truck.


JMHO

I'm new to diesels and I read here that it is good to let them idle to cool down the turbo. Question is: is this necessary if it was just a short trip to the store. I just had a Astro Start installed so I can let idle with the key out. I can understand letting it idle after a longer trip or towing? Thanks, Greg





How are superchips v/s Edge?? And is it ok to use a "chip" in the lower settings without intake and exhaust modifications?

I am at 8,500 on my 04' LLY, not sure on the hours (i'm at work) but i was averageing 14.9 this is mostly hwy mi. I just started useing stanadyne fuel additive and now see 15.0 same driveing habits (no hot rod stuff) well sometimeshttp://www.dieselplace.com/forum/smileys/smiley36.gif Just thought I would share.

If the truck is warm their is no need to leave it idling (unless it is for heat/ac or pto ops) UPS has a billon trucks out there. They shut them off at every stop (at least they are supposed to). They have cubicles full of engineers and bean counters figuring out what works best.

[QUOTE=ssgreg]I'm new to diesels and I read here that it is good to let them idle to cool down the turbo.


If you have been running it hard you want to let it idle for about 5-10 minutes to let the turbo cool down.

5-10 minutes may be a little excessive. . . 1 or 2 is probably sufficient. There has been advice to let EGT get below 300 before shutting down. My truck will not reach that level, no matter how long I let it idle, so I let it get below 350 and shut it down, usually about a minute in the Summer, less in Winter. . .

There are many opinions on the subject of diesel idle but here goes and why! I do not suggest ideling a diesel engine for more than five minutes. A few years ago the American Trucking Association did some testing and confirmed that "one hour of ideling time is equivelant to five hours on the road engine ware". I have to agree with this conclusion because every fleet that idle their vehicles for long periods and do engine oil analysis have excess engine ware. The diesel engine is very inefficient at idle never mind the reduced water jacket temps. The engine oil analysis woiuld show a great deal of lube oil sooting, high counts of iron in the engine oil and high fuel content in the engine oil. Another problem you may encounter in time is a restricted or blocked CAT.
The best thing is to shut it off!

monty,

good post. . . There's probably a balance between letting the turbo cool down and excessive engine wear. . . the high iron counts would scare me. . .