TomTom 6.0 MPH accuracy?

[antonyj]

Does anyone know just how accurate the MPH reading on TT6 will be?

can anything affect how accurate it is? I run TT on my O2 orbit PDA.

[droopsnoot]

Generally, at a steady speed and with a decent GPS position fix, a GPS speed display will be more accurate than a car speedometer. A car speedometer is affected by a number of factors, such as calibration and tyre wear. Under hard acceleration or braking, the GPS speed will "lag" behind the actual vehicle speed, but at a cruising speed it will be accurate.

Having a poor GPS signal can reduce its accuracy - the speed is calculated by the GPS receiver based on the current position and previous position, and the time change between the two positions, so if the signal is poor this will make the GPS receiver think it has moved a differing distance than it really has. This inaccuracy is more noticeable at very low speeds.

Edited by droopsnoot on Tuesday 1st May 15:23

[JWB]

I have a Stack dash in my car which I very carefully calibrated. It matches my Tom Tom 1 exactly. I have had 2 TT1`s anf they both matched.


The GPS does take a bit of time to react but at steady speed I trust the speed reading.

In a friends Audi A3, the speedo was 8mph over reading!