Speeding trucks: Driving faster than 100km/h: Truth or Myth

Vote for Pedro on 22/06/2019 - 10:34
Last edited 23/06/2019 - 19:31

We know trucks are limited to 100km/h and some (not sure if all) have speed limiters. We’ve all probably also experienced driving the speed limit on a freeway and being overtaken by a truck.

What is the experience of OzBargain members and thoughts.

Dashcam evidence links encouraged :-)

Ps. Just because it’s downhill, it's still speeding.

Update: Speed check using Waze

M5 run between Fairford Rd and Hume Hwy Liverpool both directions. Was able to reasonably sit speedo on 100. Waze showed mostly 98 with the occasional dip to 97 with a quick return to 98.

Not scientific as it relies on me judging the 100 speedo mark and other variables but gotta love Toyota. 2% is fair.

Poll Options expired

  • 257
    Happens all the time
  • 14
    I’ve seen it occasionally
  • 12
    Doesn’t happen!
Automotive

Comments

      • spaceflight on 23/06/2019 - 22:57

        GPS is much more accurate than that

        GPS can be more accurate. That does not mean it is always more accurate.

        Your GPS probably is not calibrated, your car speedo is.

        • Euphemistic on 24/06/2019 - 00:05

          I think I’ll trust the gps. It is based on a system that is used for accurate survey work and the military, even if we get reduced accuracy for civilian use, over a mechanical sensor that translates to a voltage to drive a needle round a dial from rotating tyres that wear out along with all the other drivetrain variance.
          GPS is accurate to within a metre or so, the dial in your car is accurate within 10%. It costs a fair amount of money ti get a display accurate to 1m in a car - I’ve used them for work, and they need to be recalibrated regularly. The Speedo won’t ever be recalibrated in most cars.

          • spaceflight on 24/06/2019 - 20:34

            @Euphemistic:

            It is based on a system that is used for accurate survey work.

            Water is used to make chemotherapy, that doesn't mean drinking water will cure cancer.

            The GPS technology used by a surveyor is not the same as you have in your car.

            GPS satellites transmit two navigation signals identified as L1 and L2. A typical receiver will only listen to one of these.

            To listen to both signals you generally need a differential grade GPS device and they are expensive.

            Accurate survey work uses a rover and a base station to use a minimum of 8 GPS signals and potentiality an external data source from a known fixed position.
            The setup looks like this
            https://www.e-education.psu.edu/geog862/node/1828

            • Euphemistic on 24/06/2019 - 20:59

              @spaceflight:

              Water is used to make chemotherapy, that doesn't mean drinking water will cure cancer.

              But the active ingredient is not water is it?

  • skillet on 23/06/2019 - 14:19
    +1

    Guess what? Trucks are also driven by human so they can go above the limit. Just drive carefully and mind your own speed, unless you are a passenger in the truck.

  • [Deactivated] on 23/06/2019 - 15:31

    I have a dedicated GPS speedo on the dash.

    Was recently on the M7 cruise control on and GPS on 101K. Came up to a long line of cars , maybe 25 to 30. Pulled out and passed them. At the head of the queue was a Highway patrol car. He didn't blink as I went passed. My guess he was doing around 95 and having a good old laugh at the idiots lined up behind him. My in car speedo was reading 108.

    At least I know my GPS speedo is accurate.

    • Vote for Pedro on 23/06/2019 - 15:33

      Why would you call people relying on their speedo as ‘idiots’?

    • spaceflight on 23/06/2019 - 23:14

      At least I know my GPS speedo is accurate

      Have you had it calibrated?

      • muncan on 24/06/2019 - 20:03

        By Stephen Hawking himself

      • [Deactivated] on 25/06/2019 - 12:34

        Read my full post.

        • spaceflight on 25/06/2019 - 17:56

          I did.

          Your anecdotal evidence that your GPS is accurate is only anecdotal.

          You could have been going faster than 101 but not fast enough for the police to give you a ticket. You could have been doing slower too.

  • Ken1977 on 23/06/2019 - 15:56
    -1

    Ford is big on having the speedo reading higher than actual. 107kph is actually 100kph, and this works a bit in their favour as if it looks like you've done 107km. When you've only done 100km. Over a tank of petrol you've done 535km when it's actually 500km. Artificially increasing your fuel economy.

    • Vote for Pedro on 23/06/2019 - 16:01

      Would’ve thought this would be a commodore trick to make you feel like you’re going faster than you actually are ;-)

      • SydStrand on 25/06/2019 - 21:22

        Ford…. Commodore?

        • Vote for Pedro on 25/06/2019 - 21:28

          Going back to the days of falcon v commodore. Some humour.

          • SydStrand on 26/06/2019 - 22:22

            @Vote for Pedro:

            Ford is big on having the speedo reading higher than actual.

            Would’ve thought this would be a commodore trick to make you feel like you’re going faster than you actually are

            Did you think Ford made Commodores?

    • spaceflight on 23/06/2019 - 23:01
      +1

      and this works a bit in their favour as if it looks like you've done 107km. When you've only done 100km. Over a tank of petrol you've done 535km when it's actually 500km. Artificially increasing your fuel economy.

      No it doesn't.

      The speedo reading does not impact the distance calculation.

      In your example if you drove for one hour with your speedo showing 107 km/h your car would tell you that you have driven 100 km

      • Ken1977 on 24/06/2019 - 08:57
        -4

        So genius how does it work then. So the car secretly knows it's actually doing 100kph but it just shows you 107kph on the speedo and the digital display in the cluster.

        • stumo on 24/06/2019 - 09:26
          +2

          Thats exactly how it works Einstein, its in the ADRs. The ODOMETER has to be 100% accurate. The SPEEDOMETER had to read high. By law.

  • [Deactivated] on 23/06/2019 - 16:12

    Probably because they have NFI. Same as the idiots that go past a 60k speed camera at 45k. Or the ones that see a patrol car parked on the M4 500 metres ahead and jump on the brakes even though they are doing less that the speed limit.

    • Vote for Pedro on 23/06/2019 - 18:54
      +1

      There you go with that ‘idiots’ thing again. Seems like 93% 94% of poll respondents apparently have ‘NFI’ and are the same as ‘idiots’.

  • Jinxed50 on 23/06/2019 - 16:17
    +2

    Without getting into the debate about Speedo accuracy trucks are definitely speed limits to 100.

    What you need to consider is that like most industries they fully take advantage of any leniency given. They are well aware enforcement doesn't start for a certain number of kilometres.

    This leniency is to account for adr rules, speed measuring device accuracy and a few other things.

    Just as in a car in NSW at least No one gets a ticket for 1km over the speed limit similar thing for trucks. Those few kilometres over the limit make a large difference over the number of kilometres traveled by that truck in a year.

  • [Deactivated] on 23/06/2019 - 19:21

    Please explain how the poll questions relate to my posts.

    Happens all the time

    I’ve seen it occasionally

    Doesn’t happen!

    • Vote for Pedro on 23/06/2019 - 19:27

      Oh sorry, I thought you were posting in relation to the forum topic. Silly of me to assume that.

      Hint: try the reply option next time

  • [Deactivated] on 23/06/2019 - 20:18

    there are over 20 posts on this paje alone not mentioning trucks. The discussion switched to GPS speedos on the first page.

    • Vote for Pedro on 23/06/2019 - 20:58

      See that reply option? Try it. I promise it’ll change your life.

  • [Deactivated] on 24/06/2019 - 11:48
    +1

    Long time truck driver here - I've never heard of a truck having it's speed limiter disabled in WA. I have heard of it in the news and when it has happened they have gone to the company and gone over every vehicle.

    Company's just don't do it because they will get caught pretty quickly and the consequences are not worth it.

    Most trucks won't accelerate past 100 but if your going down a hill they will go faster than a hundred and drivers do this to help get up the next hill.

  • Baghern on 24/06/2019 - 15:55

    I recall around 10 years ago, we were late to a meeting in Canberra, driving from Sydney.

    We trailed a truck from a safe distance in the left lane, we were going around 130kmph

    When all of a sudden another truck zoomed right past us.

    edit: Just noted other peoples post, that increase in regulation around the same time means this is highly unlikely now

  • Miss B on 24/06/2019 - 22:04

    In my experience, drivers/riders of all types of vehicles regularly break the law. Pedestrians too.

  • twister292 on 24/06/2019 - 22:56

    What about some truck operators getting the vehicle complianced and then changing to larger diameter tyres? If the checks by police are only done on ECU, simply switching to larger tyres for the same ECU/speedo calibration will gain them some speed without making it apparent on either the ECU or the speedo itself.

    Of course with larger company fleets that would be a no-no, as they would be simply relying on whatever OEM spec tyres the trucks came with, plus GPS tracking etc.

    • Smith1988 on 24/06/2019 - 23:43

      Just about every prime mover uses 11r’s for drives which is the largest tyre you can legally fit on a 22 inch rim. Even if it was calibrated for a 275 or 295 tyre, they would pick it up on a ECM scan pretty quickly.

      There are easier ways to modify the limiter, and undetectable as well. Or in some vehicles it’s as simple as spinning a relay 180 degrees and plugging it back in which you can do in a Volvo. Gets you 118kmh on the pedal.

  • sghetti on 25/06/2019 - 10:18

    A lot of trucks are speed limited to 90. But in some trucks (not sure about all of them), the limiter is disabled by pulling a fuse out.

    At my first job working in a warehouse, we had a truckie come in and tell us they had a truck compliance check out on the main road, he told us he had the fuse for the speed limit removed, but had a piece of string attached so that it sat in the compartment and was easy for him to plug back in when he needed to.

  • dufflover on 25/06/2019 - 10:35

    It's definitely not a myth

    https://www.abc.net.au/news/2012-07-22/truckers-under-micros…

    • Vote for Pedro on 25/06/2019 - 10:40

      Geez, in May —> 1000 Offences in NSW alone.

      • dufflover on 25/06/2019 - 10:46

        That number was probably because it was the first time they went on a blitz on them, but still I would expect that "naturally" a number will be back on disabling again, with quick workarounds like mentioned in the above comments.

        That's until someone discovers one fitted with the Navitron Autodrive System.

        • Vote for Pedro on 25/06/2019 - 11:11

          The thing we all know is that even blitzes only get a portion of offenders.

  • Brouw3r on 25/06/2019 - 19:05

    Last week I was sitting at 105 (by GPS, 110 on speedo) in a 110km/h zone behind a Road Train with a 90km limit sign on the back. I've also driven a rental 25-seater buses that stopped accelerating at 105km/h on the speedo.

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