OT Sat Nav

[Huge]

How odd. I always considered you to be a reasonably sane and constructive member of this newsgroup. It appears I was wrong, and you're batshit crazy.

[Dave Plowman (News)]

Elsewhere, I saw the calcs on the effect of new against worn out tyres on the speedo reading. It's tiny, and only effects it in the allowed direction. So still no reason not to start out with a far more accurate instrument than most makers supply.

The thing is you can take as many examples of a model as you want - and you'll find the speedo error is pretty consistent. If the current tolerance was really needed, it wouldn't be.

[Mike Barnes]

Andy Champ :

Hmmm, have you ever driven with two GPSes on the go at the same time? I have, and they disagree, by up about 2 mph IIRC. The difference varied but one on average one gave a higher reading than the other.

[Mike Barnes]

True. But if there's a chance that you'll get a £60 fine and 3 points for your trouble...

[dennis]

I think the water proof bike sat navs have bigger batteries in them and last several hours.

[dennis]

Tow bars are quite useful too, you can rip the front off the nutter that is nudging you.

[Tim Streater]

What's the radius of a wheel OK my C4 is diameter 62cm so

310mm radius. If that's reduced by 6mm as the tire wears that's about 2%.

[Dave Plowman (News)]

2% at worst would be a perfectly acceptable error. 10%, not.

[F]

2% would be acceptable in most cases but my year old Astra started out at an illegal 11% and so I'm looking at 13% when the tyres wear and even more fingers in specs camera zones (when I've not bothered to take the sat nav with me to get a more true reading).

[tony sayer]

Just wondered how I managed to get to Four locations in London the other day and all of that without a GPS. Funny but ISTR looking at those locations on Google maps first..

And went straight there. I do carry a decent Garmin unit and can connect that up to a mapping applications for recording radio system and network coverage with calibrated receivers but as to basic road Nav in the inbuilt positioning system works very well;)...

[polygonum]

And having fundamentally inaccurate speedos encourages people to make a bit of an allowance "I won't get done if it shows less than 78 mph". And then adding another 10% for the unlikely-to-be-caught so you are OK on a

70 mph road at an indicated 85 or so. This is crazy. Especially if you switch vehicles regularly and might have no idea of the inaccuracy of one form another.

Let's have accurate speedos.

[Alan]

In message , "dennis@home" wrote

And around my way will attempt to route you around one slow moving grid lock to a slower moving grid lock :)

[Alan]

In message , John Rumm wrote

And helpfully says "do a U turn" as you approach it from one direction.

If you drive past the TT preferred turn off it is very good at telling you to do a U turn from the RH hand lane on a fast moving dual carriage way through the little service gaps with the bollards in the way :)

[ARWadsworth]

Whey would you think that the bloke that removed the wheel nuts from a non paying customers car is sane?

[F]

When we first got the Astra I wasn't aware of how inaccurate it was but I soon started to notice how often I was being overtaken, then the ridiculously long queues behind me (and the finger) in specs camera stretches.

[Huge]

Jesus, is today 'National "tu quoque" Day', or what?

[Alan]

In message , Huge wrote

Or safety.

[ARWadsworth]

et tu, Brute? I always new you were insane, that's why I like you.

I have done good things. I helped when a woman was threatening to jump off a bridge. In fact I missed a days work because of my help. So I am not all bad.

[dennis]

Well that's 2% from tyre wear. Then there is tyre inflation pressures. Then there is load And there is the error introduced by tyre deformation at speed. It makes me think that 2% was a tad optimistic.

And that's before any manufacturing tolerances.

[dennis]

Well a TomTom which is less than about three years old will allow you to edit the map and remove the gaps if they are no longer there. It then uploads the edits to TomTom and they will correct the map for everyone when you next download the maps and/or edits done by others.