speed accuracy

mutleyeng · Occasional Visitor Joined: Dec 28, 2005 Posts: 10

hi all,
still pretty new to my Go 300.
Recently noticed i can view a speed readout, so gave it a go, and seems it significantly different from my tacho (tacho steady at 30, the tomtom will report 25 mph).
Best guess as to which is closer to the truth?

alix776 · Posted: Sun Jan 01, 2006 11:50 pm Post subject:

if you in a straight line on a flat road then the nav is very very acturate
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currently using aponia truck navigation on windows phone. Good bye IOS don't let the door hit you on the way out .

Oh the joys of being a courier.
device Lumia 950 xl

MELennium · Posted: Sun Jan 01, 2006 11:51 pm Post subject:

The sat nav is much more accurate than your car, manufacturers always over compensate in case they might get sued.
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TomTom Go 910 (3) v.6.522 Map Western Europe v.650 with useless TMC receiver
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Ex. owner TomTom 910 (1) Returned Faulty
Ex. owner TomTom One v.5.420 Map UK v.605
Ex. owner Garmin i3 v.2.7 Map UK V.7

TT300_Owner · Regular Visitor Joined: Jul 29, 2005 Posts: 78

When speed cameras were introduced, some powers that be wanted them to take nice pictures of anyone who went even 1mph over the limit. However, tests showed that speedos on cars are not 100% accurate, and even changes to any one car can change what the speedo reads. So, the cameras (I'm reliably told?) are set to go off if you are doing over the speed limit + 10% + 2mph... So if you are in a 30mph zone, the camera would normally be set for 35 - but don't go doing that, get flashed and blame me! Wink

:D

Because of the inaccuracy of speedos, I've seen posts where people say the TT is a much more reliable indicator of speed, especially as it is tracking your movements and calculating your speed based on time/accurate satellite distance position.

My speedo shows about 3mph above what TT shows. Still, I'd rather be going slower than I think I am - better safe than sorry :D

JLee · Posted: Mon Jan 02, 2006 2:05 am Post subject:

I've noticed the same thing. When driving at 80mph according to my tacho the TTG always shows 73.

So if the tacho is so far out does this mean the milometer is also out? Maybe my car has not really done 24000 miles after all!

Unplugged · Posted: Mon Jan 02, 2006 4:40 am Post subject:

Well if its any way to check my Tachometer is Digital but my Speedo is Analogue.

When I plot a route and reset the trip counter providing I follow the route exactly the trip counter is pretty much smack on what the distance that the Go reports even when driving down a motorway the .x miles part is pretty much the same but when traveling at 70 the speed reading on the GO will read 66.

quite how it affects an analogue trach is another thing you will have to plot a short route say 3-5 miles or so down a motorway reset your counter and drive it at 70-80 then compare results.

Oldboy · Posted: Mon Jan 02, 2006 10:43 am Post subject:

Andy_P · Posted: Mon Jan 02, 2006 5:58 pm Post subject:

If you want to minimise your total mileage, keep your tyres over-inflated! Means you travel further for one revolution of the wheels so the mileometer will under-read. 8)

Oldboy · Posted: Mon Jan 02, 2006 7:57 pm Post subject:

Probably won't do the tyres a lot of good though. Rolling Eyes

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TT 910 V7.903: Europe Map v1045
TT Via 135 App 12.075: Europe Map v1120

JimmyTheHand · Frequent Visitor Joined: Apr 16, 2005 Posts: 386

Andy_P · Posted: Wed Jan 04, 2006 2:07 am Post subject:

'Twas a joke Embarassed

Skippy · Posted: Wed Jan 04, 2006 2:38 am Post subject:

Keba · Occasional Visitor Joined: Dec 05, 2005 Posts: 15

How much tread you have on your tyres also dictates how far out your speedo will be.

Cop cars have to have their speedo <-> radar system calibrated once a day due to the difference that tread wearing can have.

This is probably more noticable on a bike than on a car, espeically if the bike rider does a lot of motorway traffic (like me!) Bike tyres are rounded and the top flattens out quite quickly if you do a lot of straight line travel. My journey length changes from 60 to around 64 miles over the age of the tyre as it wears out....
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Keba
Quidquid latine dictum sit, altum sonatur.

pip510 · Posted: Fri Jan 06, 2006 12:23 pm Post subject:

tangiers · Occasional Visitor Joined: Jan 05, 2006 Posts: 2

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