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.
Speed limiter is not based on the speedo, but the speedo may get its readings from the speed limiter. And trucks are covered by the same ADR. The speedo cannot read "under" speed (ie: speedo says 100, truck doing 110.) But there is nothing to say that it cant be bang on (ie: 100 read, doing 100 actual)
On the highway, it's easier to just mash the pedal to the floor and know that the limiter will hold it at 100km/h. Typically, most of the trucks I have driven, the limiter v's GPS (I have a 5Hz dedicated speed test GPS) it's usually 100 indicated and at worst about 98 actual in a truck. Most cars I test, its 100 indicated and about 92~96 actual.
My motorcycle was so bad that I ended up putting a "speedo healer" on it to fix it. On the freeway, I was constantly being passed. Tested it, and at 100 indicated, I was doing 88. Well under ADR. With the speedo healer on, indicated is 100, actual is 99. The same can be done for cars if you want it to read more accurately.