On navman & other car specific units?
My late model car speedo, both digital & analogue, read slower?
The_observer said:
On navman & other car specific units?
Pretty accurate.
Peak Warming Man said:
The_observer said:
On navman & other car specific units?
Pretty accurate.
I get a 3 to 4 kilometer per hour difference.
Either the navgods wrong or the cars system is wrong. I don’t know which
The_observer said:
On navman & other car specific units?
More accurate than the speedo that comes with the car – on at least all three of my last three cars.
The GPS has a time lag, so it’s about 10 seconds behind your real speed. But other than that, it’s within about 1 km/s, so completely accurate.
The car’s system is wrong. It always is.
mollwollfumble said:
The_observer said:
On navman & other car specific units?
More accurate than the speedo that comes with the car – on at least all three of my last three cars.
The GPS has a time lag, so it’s about 10 seconds behind your real speed. But other than that, it’s within about 1 km/s, so completely accurate.
The Dealership said basically what you said moll, & then proceeded to tell me the csr was more accurate. I tend to believe the navgod.
mollwollfumble said:
The_observer said:
On navman & other car specific units?
More accurate than the speedo that comes with the car – on at least all three of my last three cars.
The GPS has a time lag, so it’s about 10 seconds behind your real speed. But other than that, it’s within about 1 km/s, so completely accurate.
Dunno if the time lag is that long, when I got my Tomtom I amused myself for a while checking how quickly it responded to change of speed limits and how accurate it was with streets, I would estimate it to be measured in tens of metres and way quicker than 10 seconds.
AwesomeO said:
mollwollfumble said:
The_observer said:
On navman & other car specific units?
More accurate than the speedo that comes with the car – on at least all three of my last three cars.
The GPS has a time lag, so it’s about 10 seconds behind your real speed. But other than that, it’s within about 1 km/s, so completely accurate.
Dunno if the time lag is that long, when I got my Tomtom I amused myself for a while checking how quickly it responded to change of speed limits and how accurate it was with streets, I would estimate it to be measured in tens of metres and way quicker than 10 seconds.
The lag is inconsequential really. I’m checking the speed readings whil we in cruise control
Car magazines use GPS for comparisons but would be for consistency as well as accuracy.
Peak Warming Man said:
The_observer said:
On navman & other car specific units?
Pretty accurate.
Attractivrely accurate?
mollwollfumble said:
The car’s system is wrong. It always is.
But by no more than say 5%?
roughbarked said:
mollwollfumble said:
The car’s system is wrong. It always is.
But by no more than say 5%?
Yes, my car would fall into that range. But they aren’t adjustable, I’m guessing by the response of the Dealership.
The GPS is a lot more accurate. At constant speed it’ll be better than 0.5% out.
A car speedo before June 2006 is only required to be accurate to within +/- 10% above 40 km/h. After June 2006 they cannot under-read and still have the 10% maximum error but with an additional tolerance that I can’t remember off the top of my head. But I remember that if the errors were all added up as a maximum you could be doing about 84 km/h with an indicated 100 km/h. It’s rare to be more than about 5% slow though.
But not with a motorbike, they are often about 10% slow – It’s why I can to do 100 km/h indicated on the highway to do 100 km/h real.
Spiny Norman said:
But not with a motorbike, they are often about 10% slow – It’s why I can to do 100 km/h indicated on the highway to do 100 km/h real.
Eh?
On my motorcycles I may change the final drive front and rear sprockets for different gearing depending on the riding I will do such as track day, or touring, or commuting. To fix the electronic speedo and odometer, I use a simple device called a Speedo Healer. Have used on for years and is the first thing I do to a bike after I buy it.
They plug straight into to the wiring loom with no cutting required and allow you to calibrate the speedo. There may be a similar product for your vehicle.
sibeen said:
Spiny Norman said:But not with a motorbike, they are often about 10% slow – It’s why I can to do 100 km/h indicated on the highway to do 100 km/h real.
Eh?
Whoops, 110 km/h indicated to do 100 km/h real. That being said, I was in a 110 km/h zone and had 120 km/h on the speedo – Mr Plod on another bike cruised up next to me and pointed at his speedo. I figured that meant he thought I was going a touch fast so I slowed a couple of k’s, then he left. (speeding at the time)
The error in speedo’s isn’t always linear, it can very a bit at varying speeds so whilst I thought I was doing 108 – 109 km/h, I may have been doing 111 km/h. (though I doubt it)
GPS speedometers tend to under estimate speed on windy roads.
dv said:
GPS speedometers tend to under estimate speed on windy roads.
Yep, you have to be going in a straight line for a few seconds to get good accuracy.
Spiny Norman said:
dv said:
GPS speedometers tend to under estimate speed on windy roads.
Yep, you have to be going in a straight line for a few seconds to get good accuracy.
Morning all.
They also need to be able to see some satellites. Generally not easy on winding roads.
ChrispenEvan said:
!https://scontent-syd2-1.xx.fbcdn.net/v/t1.0-9/19275332_1528039247260809_2766046485852229312_n.jpg?oh=082cb883ac8ad40581f98c6bd0bd54a9&oe=5A0F29A4
dv said:
I thought wind had no effect on a GPS.
GPS speedometers tend to under estimate speed on windy roads.
Michael V said:
dv said:I thought wind had no effect on a GPS.
GPS speedometers tend to under estimate speed on windy roads.
It does when you include the missing e.
Michael V said:
dv said:I thought wind had no effect on a GPS.
GPS speedometers tend to under estimate speed on windy roads.
it should be “winding” road. save confusion. the Beatles had it right.
ChrispenEvan said:
I agree. Especially as I am easily confuddled.
Michael V said:
dv said:I thought wind had no effect on a GPS.
GPS speedometers tend to under estimate speed on windy roads.
it should be “winding” road. save confusion. the Beatles had it right.
;)
Thanks for the updates. Particularly the time lag much less than 10 seconds.
> It’s rare to be more than about 5% slow though.
All my most recent three cars have been more than 5% slow. So I wouldn’t call it rare. In fact, given the number of cars I pass on highways, I’d say that at least 30% of the cars on the road have speedometers out by or than 30%, and possibly as high a fraction as >80%.
Oops
> out by or than 30%
Out by more than 5%.