Attn diesel guru's: How much fuel do we use idling?

Discussion in 'Diesel Tech and 24 volts Systems' started by nickw, Mar 25, 2006.

  1. nickw

    nickw

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    Just wondering how much fuel we use idling
    I know its not very much as diesel engines are very efficient especially at idle.
    But does anyone know how much fuel a 1HD-T uses?

    2-3 liters per hour?
    I have no idea.

    Come on diesel guru's, what do most engines use.

    Cheers,
    Nick
  2. nickw

    nickw

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  3. that sounds like an awful lot, but who am I to say.
    A diesel mechanic at toyota once told me the 3B idles off the fumes of a rag soaked in diesel, now my friend always reminds me of that when i'm idling.
  4. brownbear

    brownbear Mod in Hibernation Moderator

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    This is something I never thought I would hear! Kind of an oxymoron.......


    Regarless they still use fuel, and still pollute into the enviroment. I do not recomment endless idling.

    Also IMOP idiling for long periods at low idle is going to cause damage to your engine.

    Reasons:
    1) engine temps gets to low, and cylinder wear happens due to not enough expansion. As well as other items.
    2) soot build up on valve train and in exhuast. Staglagmites on the valves.
    3)Carbon/soot build up in engine and in oil.

    Higher idle helps to eliminate these problems, but then you are burning more fuel.

    IMOP, idle only whats needed to get the cylinder head warm before taking off down the road. This could be a minute or less. Depends where you live.

    If you need to have it idling all the time, buy a ESPAR or WEbasto
  5. Well that’s good news about the idle..

    After highway driving the manual just recommends that you let your motor idle for up to 2 mins to cool down the oil in the turbo.

    GB
  6. brownbear

    brownbear Mod in Hibernation Moderator

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    definately a good practice to cool down the engine after highway bobbin..
  7. Behemoth60

    Behemoth60

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    I'm no expert, but I google...

    Not sure how this translates to fuel per hour, but the word on the street is that a diesel at idle runs an 'air/fuel' ratio(to borrow a gasser term) of 60 to 100:1. A gasser ALWAYS has to run at its stoichiometric ratio of 14.7:1. I guess you could calculate fuel consumption from that ratio...

    Let's see....
    750 RPM - call that 45,000 rotations per hour. 1/2 the rotations actually use air, so we'll call that 22,500 rotations, at 4.2l displacement (assuming no boost at idle at a volumetric efficiency of 85% is 80,000 litres of air. Air weighs .0012kg/l, that's about 95kg of air. At a ratio of 100:1, that's about .95 kg of fuel. At .88kg/l for diesel, that would be about 1.1 l per hour. At a ratio of 60:1, this would increase to about 1.8 l-hr.

    So, the science would say a 1HD-T ish kind of diesel would burn about somewhere between 1.1-1.8 litres per hour at idle. This jives with the other estimates of around 2l per hour.

    But heed Brown Bear's advice. Don't do it. A Webasto burns about 1.3ll/hr, keeps your engine warm, and doesn't have the 'cylendar wall glazing' detriment. A 1HD-T doesn't have replacable cylendar liners, does it?

    Peter Straub
  8. nickw

    nickw

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    Thanks guys,

    I don't usually exessivly idle.
    If I a going to be parked more than 5 minutes I typically shut it off.
    Longest it ever goes is 10 minutes.

    I do always give it idle down time after driving (30 seconds around town) and a couple of minutes after the highway or pulling hard.

    Cheers,
    Nick
  9. lowenbrau

    lowenbrau SILVER Star

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    Hmmm I guess it was a bad thing to leave my first BJ60 run for idle for three days over Christmas in NW Ontario one year? It was 40 below and I didn't want to risk it not starting. It used about 1/2 a tank.

    I had the winter front down. Does that make me less of a bad person?
  10. brownbear

    brownbear Mod in Hibernation Moderator

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    Yes...........:D




    We have a dodge diesel at work. It idles too much. The exhaust gets huge chunks of soot in it. Idle is wonky and I would not touch that truck with a 100 foot pole when the time comes to sell it.

    I even had dodge put in a software program to help this problem, it uses the cruise control and has a variable idle, cruiser sets it up on high idle. I personally have not tried it, but was explained how it works by the dodgy guys.


    You didn't have a good block heater to use in NW ontario? 3 days isn't too bad, bloody transports idle all over the country forever, talk about excessive pollution, I couldn't give a crap what they do to their engines.

    Nick, how you explain the idling sounds fine. 5 minutes is good. Anything over that you might as well shut it down.

    Someday I am getting a Webasto.......
  11. crushers

    crushers post ho SILVER Star

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    i can honestly say i have never had a reason to run a diesel at idle for 3 days straight but if the need was there i would have no problem at all doing it.
    bring the idle up to where you have decent oil pressure, at idle most of our Toyota diesels produce poor presure, even at 1200 rpm you have much better oil pressure.
    as for glazing the walls, if the engine is burning the fuel being delivered and if you have the fuel setting properly set, why would the fuel wash the walls?

    it is MUCH harder on an engine starting not plugged in cold weather than any amount of idling will do.

    just my view of the matter.


  12. Wayne

    Any solutions on the poor oil pressure, and is it a real problem at idle?

    :cheers:

    GB
  13. Eric Winkworth

    Eric Winkworth

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    Wayne, what would you consider poor at say 800 rpm with engine oil at normal operating temp?
  14. Technikev

    Technikev

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    My father and brother in law drive truck for a living and they both live up in northern BC where it can get real cold. Dad has a Proheat in his truck which he uses alot; sets the timer to go on 2 or 3 hours before he goes out to work in the am. If he is out in the bush for any length of time in the winter, he will run the Proheat instead of idling to heat the cab and engine coolant, but will run the truck for an hour or so a couple times a day so the battery stays charged.

    Dane (brother in law) was telling me a couple years ago about a winter he spent up in the Watson Lake area. Cold, cold, cold apparently. His truck didn't have an supplemental heater so it basically didn't shut off all winter. This is obviously except for oil changes and other service.

    Excessive idling WILL dillute your oil. If you don't believe me talk to the diesel manufacturers like Cummins, Cat and Detroit. These are the big tough drive 500k miles before a bearing roll, hauling 80000 lbs or more all day long kind of engines. And they day don't do it.

    This is EXCESSIVE idling. OK, lets use some common sense here, in that 20 mins to a half hour per day that you might idle, its not going to cause any damage as long as you perform your regular maintainance. If you only drive 10 minutes to work and run your engine for 20 minutes to warm it up in the am, and again at lunch to drive 2 blocks to the Burger King, and again b4 you go home, thats just foolish.

    If its -30C for a couple days and you can't plug in, idle your truck for gosh sakes and change your oil when you get home. If this is a persistent situation, get yourself a Webasto or a similar device. This is a hell of alot better than starting your engine with ether and running without oil for the first 30 seconds because its like a big frozen tootsie roll in the bottom of your pan.

    If you are going to idle for a period of time (in your driveway or at the 7-11, not at a red light) throttle up to 1000-1200 rpm. It raises your oil pressure to a more acceptable level and creates a bit more heat to burn cleaner. That's what that little knob is there for. Its not a cruise control.

    Common sense should rule here. A few minutes here and there is not going to do anything. Days at a time is probably not the best thing for your engine.

    Just my opinion, the Surgeon General's warning, don't run with scissors and all the usual disclaimers apply here.

    -kevin
  15. brownbear

    brownbear Mod in Hibernation Moderator

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    Its not the low oil pressure that would bother me at idle. Its the low coolant temp and the stone cold engine. (low idle). All thou diesels are fairly efficent air users at low rpm the fuel is not burning fully due to cold combustion areas.

    Bringing the idle up solves this problem.

    For big rigs idling all over the place in the extreme cold I can understand the various points. But I don't except them. These guys need to the trucks prepped for the various temps they work in. That means small heaters and maybe small gen sets to charge batteries.

    As for the heat, sounds like a problem that needs to be looked into by the truck manufactures on new builds. Like better ventilation. Insulated roof designs. Etc.

    A local trucking comany here in Smithers has GPS tracking and sensors on their trucks, they monitor speed and idling to ensure it does not become excessive. Other companies need to do this as well.
    Last edited: Mar 27, 2006
  16. I have great respect for truckers, they work stupidly crazy hours, drive endlessly and get average pay for it all. Not only that but they are the CRUX of ALL business anywhere, period.

    In Australia especially, trucks are MANDATORY and you will find that most driver training has at least one part that focusses on giving heavy vehicles right of way because quite simply, they have a job to do.

    I have many friends who drive trucks and have a license to do so myself and frankly, the fuel consumption isn't the issue. In all honesty and according to EPA figures, cows fart/burp more methane into the air than all the road traffic combined in the whole of Australia. Enjoy that one.

    Trucks over here are all electronically governed to 100kmh, you can "overspeed" to 105 briefly but as soon as you ping 105 or have been at 101-105 for more than 3 seconds, the engine brakes kick in briefly and bring you back to about 97-98 kmh.

    The most popular slogan over here and carried by EVERY vehicle of the enormously large Aussie trucking companies like Linfox, Toll and the like is on the back on a hazard sign (Diamond shape) and it says:

    "Without trucks, Australia stops"
  17. bigbrowndog

    bigbrowndog

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    Trucks over here are all electronically governed to 100kmh, you can "overspeed" to 105 briefly but as soon as you ping 105 or have been at 101-105 for more than 3 seconds, the engine brakes kick in briefly and bring you back to about 97-98 kmh.
    LOL.:eek: You are joking an having a lend of these guys.:D Pehaps some but not a lot up here.Seems you also missed the current affairs programme a while back where they followed the trucks at well over the limit and non stop from Brisbane to Cairns also Brisbane to Townsville.oh yeah remember. LOL.
  18. lowenbrau

    lowenbrau SILVER Star

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    To continue the hijack...

    The trouble is not with trucks but with truckers. They used to act like professionals but now, more and more, they are acting like children. I used to give truckers every possible courtesy, holding back traffic if they were trying to change lanes or neding two lanes for a turn, introducing myself on the CB before passing etc. Now I just don't bother. I've had so many bad experiences with jack ass drivers, I don't know where to start but the most recent was last weekend when, on a dark, extremely foggy, road I very nearly drove up the ramp of an unloading car hauler parked in the middle of the road. He had his light shut off!. I stopped and told him he was a hazard and asked him to turn on his lights. He told me to get lost, he wasn't running his batteries down. There's a guy who should do a little more idling. :mad:
  19. crushers

    crushers post ho SILVER Star

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    there is a guy that needs a baseball bat up side his head.
    call the cops and report him, what an asshat!
  20. Tapage

    Tapage Club 4X4 Panamá SILVER Star

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    It's a real problem be at idle for much time .. I remember sometimes when my 2H still idling by what 6 or 8 hours .. I'm not sure if I get problems in the future .. but right now nap ..

    In our mud trails sometimes, get a big and huge swamp ... if I'm 6 or 8 in the row to passs I need to await all go over .. :D and wait my turn to fun !

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