gps v speedo

Be aware there is a slight delay on the GPS because of signal transmission time, but the speedo is instantaneous.
The display on the GPS may actually be an average of several readings, to avoid jitters from multiple readings.
Driving in a straight line the GPS should be fine, but when curving variations are possible.
Also, interruptions to the satellite signal may cause the reading to freeze.
It is possible to be stopped and notice the GPS is still showing movement, while the speedo shows the vehicle is stopped.

I drive to my speedo - because I've double checked it, and it's about 5kmh under.. I figure that way I'm just be cautious driving past speed cameras. On my daily trip to work there are 7 that I know of!

Quote:

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Originally Posted by Tombie

Speedo - I went into the CCF and modified it so my Speedo and True Ground Speed are a match. [biggrin]

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Me, too.
Mind you, it does my head in on the highway especially when behind Toyotas. I swear their speedos read 10 under on factory settings!

Tombie, what setting did you adjust? For me it was Tyre Size MSB - IPC. Tyre Rolling Radius had no effect.

Quote:

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Originally Posted by Redtail

Me, too.
Mind you, it does my head in on the highway especially when behind Toyotas. I swear their speedos read 10 under on factory settings!

Tombie, what setting did you adjust? For me it was Tyre Size MSB - IPC. Tyre Rolling Radius had no effect.

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It’s been a while. I think I did the same....

Speedo:
My Disco2 has a speedo calibration unit installed, so 100kmh reads as 100kmh, 55km/h reads as 60km/h.
My Audi's speedo reads correctly against the GPS.

I have checked my speedo several times against gps.

I am running 265/65x17's and know if I'm showing 110 on the speedo I'm actually doing 101.

Consequently if I'm showing about 120 I know I wont get booked in a 110 zone.

If I actually sit on 110 on the M1 posted speed I constantly get brake checked.

Either!

105 km/hr on the speedo = 100 on the GPS, so I just put the cruise control on 106!

I also know exactly what speed I am going,so don’t hold up the trucks that are sitting on an actual 105km/hr in a 100 zone,

Trucks doing 105K in a 100 zone , isn't that e-legal . [bigwhistle]