sat nav more accurate ?

Honest John Back Room » Motoring discussion
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Fri 16 Sep 2005 22:43
sat nav more accurate ? - top
A few weeks ago had sat nav unit fitted using tomtom software,
have just noticed that you can switch over to see the speed of the car displayed, the car speedo appears to read approx 10% faster than the sat nav, which one is likely to be more accurate.
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Fri 16 Sep 2005 22:48
sat nav more accurate ? - JH
satnav. Car speedo is permmited to read between +0 and +10% of actual speed. Manufacturers err on the high side for a variety of obvious reasons.
John
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Sun 18 Sep 2005 11:05
sat nav more accurate ? - Happy Blue!
Will the TT GO300 or GO500 do the same?
--
Espada III - well if you have a family and need a Lamborghini, what else do you drive?
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Sun 18 Sep 2005 11:09
sat nav more accurate ? - Honestjohn
Satnav is 100% accurate because the position of the car is crosspatched by several satellites at the same time. True speed in 'Autocar' road tests is read by GPS, not by timing or measuring devices.

HJ
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Sun 18 Sep 2005 17:24
sat nav more accurate ? - martint123
Satnav is 100% accurate

Only if you are going in a straight line on the level at a fixed speed. Going round curves or corners or up and down hill reduces accuracy of consumer systems as all it does is measure how far you have moved in a horizontal plane in a fixed time (seems to be around a second).

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Sun 18 Sep 2005 14:41
sat nav more accurate ? - Altea Ego
Yes TTGo 300/500/700 have a speed display int he information bar at the bottom o fthe scrolling map/route
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Sun 18 Sep 2005 11:13
sat nav more accurate ? - islandman
My Tomtom Go 500 is similar - speedo on 75 tomtom says 71.
As stated, I think it's generally the case that car speedos read slightly higher than true.
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Sun 18 Sep 2005 14:46
sat nav more accurate ? - Armitage Shanks {p}
My 307 speedo reads 3 mph faster than GPS across the speed range and checked against 2 different GPS devices.
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