Mindless idling?

Discussion in 'Fuel Economy' started by Mendel Leisk, Sep 23, 2014.

  1. Mendel Leisk

    Mendel Leisk 2010 Prius (CAN Touring) Staff Member

    Noticed our neighbour across the street got himself a flat: had a tow truck at the end his driveway, and a guy working, pulling off the flat and getting the temp spare on.

    About 10 minutes later I opened our front door to retrieve the morning paper, and hear the low rumble of the tow truck, idling away. No lights flashing, it's just parked there, idling. From the time the guy showed up, to when he left, maybe 30 minutes transpired.

    I'm guessing it's diesel. Is this something they have to do, leave it running? Or just old school?
  2. ALS

    ALS Super Moderator Staff Member

    That's nothing you should be at my local gas station mini market up the street in the morning.

    The lottery players jump out, run in, grab a cup of coffee, play their numbers and buy their scratch offs while the whole time their vehicle is idling out front. :(
  3. I volt Old school. I was amazed at how many guys left their diesels idling forever when I was hauling trailers.
  4. RedylC94

    RedylC94 Well-Known Member

    But why? To maintain the cabin at a comfortable temperature? Afraid the engine won't start after shut-down? Afraid of wearing out the starter? Aurally marking their territory? Just don't care about fuel cost?

    The wrecker guy may not care, if his boss is buying the fuel. Even if he's his own boss, he's happy because the cost of fuel to idle that half-hour is trivial compared to what he'll charge.
  5. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    We have a guy here at work who eats lunch in his car and starts the engine , I guess for his whole lunch period. And it's NOT HOT OR COLD outside. Maybe he just wants to keep mice from making a nest in his heater ducts ? I will ask him one day.
  6. phoebeisis

    phoebeisis Well-Known Member

    Yeah that is OLD SCHOOL DIESEL stuff.
    The claim back then was
    1) Diesels harder to start when cold(really really a long time ago-when diesel WOULD kinda gel) yeah this was true 30's 40's 50's 60's maybe 70's 80's-big rigs and pickups with crummy glow plugs)
    2) They use sooo little fuel idling-why bother(tiny bit of truth to that-depending on what you consider tiny)
    3)Starting up diesels is when the wear happens-so engine won't "wear out" as fast if you let it run with oil warm and circulating.OK tiny bit of truth to this also-but modern engines-actual oil lubed parts-DON'T WEAR OUT- something else breaks instead(various fuel system components)
    4)Stupid and lazy- always a factor
    ALS-any nice trucks-perhaps I should come up to PENN and steal one of them??Actually the address of the mini mart would be helpful-??
    Any Ram 3.0 TD yet??

    What kind of DSOB DMF leaves his EXPENSIVE vehicle running while he isn't in it??
    Perhaps I should "put an order in" for that Ram 3.0TD entire engine bay transmission drive shaft I was planning to "eventually" stuff in the 1998 Suburban.
    I was thinking-wreck salvage-but a nice recently ripped off one might do.

    Yes I am kidding
    But DUMB LAZY is the WHY folks leave their vehicle running when they aren't in it!

    PS Black vehicle in summer-plenty HOT- almost forgivable except for the someone will steal it aspect!!
  7. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    Black vehicle in summer : leave windows open an inch. No excuse , case closed.
  8. Mendel Leisk

    Mendel Leisk 2010 Prius (CAN Touring) Staff Member

    I used to catch a ride home with a coworker in his diesel pickup. He would start it up and let it run 5 minutes. But this was with cold-start, and he said he was uneasy with it, but the Owners Manual stipulated to do this. Still, that's a different situation, and only 5 minutes.

    I recall a few decades back someone hit-and-run us, and when we were talking to cops they fired up their cruiser about halfway through the discussion, and it ran a good 20 minutes, just sitting in a driveway, before they finally took off.

    Nowadays I'd be climbing the walls, just thinking about my mpg stats tanking, lol.
  9. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    From what I've observed , police officers around here NEVER turn off their engines.

    I'm guessing , from this and the way they accelerate , that they don't pay for their own fuel.

  10. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    Of course not. YOU do.
  11. 08EscapeHybrid

    08EscapeHybrid Moderator

    If I may interject some wisdom from my days in the rescue squad... (I was the vehicle maintenance officer). A lot of this may apply to tow trucks.

    First of all, its considered an emergency vehicle. You DO NOT shut it off when you are away from your station. If the truck does not start at the station, you can always take another truck. If you're out and shut it off, and it doesn't start, you're screwed.

    2. With ambulances at least, the drugs and IV fluids need to be kept at room temperature, as excessively hot or cold drugs and fluids will cause problems if you try to inject them into a patient's veins.

    3. Diesels use relatively little fuel at idle.

    4. Turbocharged truck engines should be allowed to idle and cool before being shut off. I used to preach to my crews "The turbocharger is not a heat sink"
  12. Unleaded

    Unleaded Well-Known Member

    I have read and heard that diesels (at least the semis) idle at about 1 gallon per hour. To me that is a lot!

    Anyone here with a scangauge drive a semi? What does it report?
  13. Gord

    Gord Super Moderator Staff Member

    I've done a quick calc for my 2.2 Honda Diesel i-CTDi (like the one in the Euro Civic Wayne drove in 2007) and it looks like it uses ~ 0.33 galls/hour when idling as my Ultragauge was showing 168 - 152mpg on a 55 to 50 engine on glide this morning.

    It really annoys me when I hear/see people idling for no apparent reason....
  14. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    Can that be right, Gord ? My petrol Honda only seems to use .25 gph , per Scangauge. I would think the diesel would idle at closer to one litre per hour. Mike , Nathan ?
  15. Gord

    Gord Super Moderator Staff Member

    Hi Edwin - not sure, I may be getting my math muddled :(

    I'm trying to convert everything from mpgUK to mpgUS which doesn't help.

    My UG was showing about 202mpgUK at 55mph dropping to 183mpgUK at 50mph so to get galls/hour I divided the speed by the displayed mpg:
    55/202 = 0.27 UK Gallons per hour.

    To convert Uk gallons to US gallons I multiply by 1.20095 so I thought I needed to multiply my calc gallsUK/hour by this number to get gallsUS/hour seeing as US gallons are smaller than UK gallons so I use more an hour.

    Have I got this totally wrong?

    On the third screen on my UG I've got G/H Inst as one of the gauges so I'll try and remember to have a look tonight on the way home....
    Last edited: Sep 25, 2014
  16. ALS

    ALS Super Moderator Staff Member

    My fuel sucking pig Volvo with a 2.9L I6 burns .4 gallons in gear and .3 in neutral. Needless to say it spends a lot of time in neutral went stopped.
  17. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    I'm always in neutral when stopped , hopefully long before stopping. I never measured gph in D , only neutral. I'm finding out JUST how many times a Honda automatic shifter can handle D-to-N-to-D-to-N . No problems yet.
  18. Gord

    Gord Super Moderator Staff Member

    Ok, I had a look and it was between .24 and .25 UK G/H so around .29/.3 US G/H. I would have thought it would be lower too Edwin.
  19. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    I re-checked mine today , after about 30 miles of driving and sitting stopped for about 10 seconds. In neutral .20-.21 gph. In D , .25. If SG is correct , I'm pleasantly surprised.
  20. The Doctor

    The Doctor Old Dude, New Car

    I'm not in favor of "Mindless Idling" but sometimes idling is NOT mindless.

    For instance, one day this past summer, I was trying to get some badly needed yard work done, but the air temp was 105 degrees F.

    I'm 71, so I can take just so many minutes of that temp before I need to sit down and cool off. So I pulled my little car up close to where I was working and with the AC on FULL, I left the engine running. When I'd feel the heat getting to me, I'd jump in the car and cool off for a few minutes before getting back to work. Idling with a purpose.

    Apparently, with the new computer controlled Diesel engines and a completely different Diesel Fuel mix, endless idling is no longer Required.
    But just stop by the local Truck Stop and you'll hear parked diesels idling all over the place.

    With all the appliances in Semi Trucks these days, that require Power, idling is the only way to keep the batteries charged. Again, idling with a purpose.

    Cheers mates and Happy Holidays

    The Doctor :cool:

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