European speedos with 6% "Error"

[Ronin]

so how without a gps can i messure out if my speedo is out ?

Ride past a cop at a steady 150 indicated and see what the ticket says.

[Sam I Am]

Ride past a cop at a steady 150 indicated and see what the ticket says.

PMSL thanks for the advice.....

[Ronin]

PMSL thanks for the advice.....

No charge...... excludes gumment revenoo charges

[p.dath]

so how without a gps can i messure out if my speedo is out ?

Find someone else who has checked their speedo against a GPS, and then ride along side them when they are doing a set speed.

[p.dath]

Apart from the spelling, no. 94 plus 6% isn't 100. And it's "bang smack in the middle" of what?

Using the formula, the tolerable error range when your speedo says 100km/h would be 0 to 12 km/h. So if you were building a speedo, and wanted to play it safe, you'd probably use the middle of that range.

When I first made the post it was based on some info a BMW car dealer say to explain why the BMW's did not say 100km/h when the true speed was 100km/h. The dealer said it is a legal requirement to have a 6km/h error.

However, since reading the regulation myself it is clear that is not the exact case. An error range is allowed, as opposed to a specific value, and it it so happens that 6km/h happens to be the mean of that error range.

[boomer]

Using the formula, the tolerable error range when your speedo says 100km/h would be 0 to 12 km/h. So if you were building a speedo, and wanted to play it safe, you'd probably use the middle of that range.

When I first made the post it was based on some info a BMW car dealer say to explain why the BMW's did not say 100km/h when the true speed was 100km/h. The dealer said it is a legal requirement to have a 6km/h error.

However, since reading the regulation myself it is clear that is not the exact case. An error range is allowed, as opposed to a specific value, and it it so happens that 6km/h happens to be the mean of that error range.

so.... you should think before you quote 'fact' and my workings were correct!

[boomer]

Not quite. I think this is the way it works.

v1=100km/h (displayed speed - how fast you think you are going)
v2=88km/h (actual speed you are going, ignoring fraction)

The rulle requires v1-v2 (which equals 12km/h) to be less than 0.1v2+4 (which equals 12.8km/h). v1-v2 must also be above zero.

So if you were a manuafcturer and wanted to sit in the middle of that range, then the speed offset would be 12/2 - or 6km/h.

Which supports what I said, that when the speedo displays 100km/h the actual speed (as report by GPS) is 94km/h - or a 6km/h error. Bang smack in the middle.

Make sense?

dude i read teh web pages, that makes sense.. you're making the shit up as you go along...

may i suggest in future u make a claim and point straight to your reference material. That way it cant be lost in translation!

[sinned]

My experience is that there seem to be a lot of paranoid drivers out there, who (a) implicitly believe in the accuracy of their speedometer, and (b) believe that if they exceed 100km/h, they will be convicted of murder. It's really bloody frustrating to be driving following someone who's traveling at 90-95km/h, seemingly convinced they're sitting on the speed limit.

It is extremely frustrating when they sit in the fast lane beside another vehicle. This is not such a problem when on a bike but a real pain if in a cage. The Wellington motorways are full of slow drivers hogging the fast lane.

It wasn't until I bought a new Mazda3 that I worked out why many drivers sit on 40 - 45kph in the commute to work. The Mazda speedo is out by 6kph at all speeds. My other car, 98 Corolla, has a speedo that reads spot on.

You're still bargaining on a cop not being an arsehole and doing you for anything over 100km/h which he is legally entitled to do.
I do the same of course, try and sit at an actual 109km/h everywhere but realise that yes, I could get a ticket for that.

Cruising in the discretionary ticketing zone is risky. When I see a cop or the radar detector warns me there is one around I drop the speed to 100kph. It doesn't make sense to antagonize them.

[Badjelly]

Mrs Jelly & I went to the trouble of calibrating the odometer and speedometer of our 1989 Ford Telstar s/w (a marvellous vehicle for relaxed touring by the way) on one of those marked-out sections of the road they used to have. Odo was 5% optimistic and the speedo another 5% optimistic relative to the odo, making the speedo 10% optimistic. (Yes Hitcher, I know 1.05*1.05 does not = 1.10. I'm using a first order truncation of a binomial expansion here.)

Jap import Mazda Familia of the same vintage is much more accurate, only a few % over.

I'm pretty sure the Scorpio speedo reads a bit high too.

Our Massey Ferguson tractor doesn't have a speedo and on the quad bike the speedo needle fell off a couple of years ago, so I can't report results for those.

[NDORFN]

Mrs Jelly & I went to the trouble of calibrating the odometer and speedometer of our 1989 Ford Telstar s/w (a marvellous vehicle for relaxed touring by the way) on one of those marked-out sections of the road they used to have. Odo was 5% optimistic and the speedo another 5% optimistic relative to the odo, making the speedo 10% optimistic. (Yes Hitcher, I know 1.05*1.05 does not = 1.10. I'm using a first order approximation to a binomial expansion here.)

Jap import Mazda Familia of the same vintage is much more accurate, only a few % over.

I'm pretty sure the Scorpio speedo reads a bit high too.

Our Massey Ferguson tractor doesn't have a speedo and on the quad bike the speedo needle fell off a couple of years ago, so I can't report results for those.

I'm infinately more interested in how fast you Massey Ferguson tractor can go than the accuracy of it's speedo.

[smoky]

Thought the title was about Europeans wearing speedos

[YellowDog]

Speed is a relative illusion.

If your speedo says 120kph, whether you are doing 125 or 115 changes very little apart from the few minutes earlier later you will arrive at you destination
(after being stopped by the cops).

When I drove in the UK motorways, my speedo rarely stated less than 130kph. That was an acceptable speed in those days and you would not ever get pulled over. I now use the NZ motorways at 100 - 120kph and do not get stopped either.

Psychologically, 100kph apprars to be a higher number than 80mph (even though it is slower)

I understand that the Police unofficially accept that speedos may be upto 10% out and hence you don't get pulled at 109kph.

This may or may not be correct?

[Badjelly]

I'm infinately more interested in how fast you Massey Ferguson tractor can go than the accuracy of it's speedo.

Well, it's hard to know because it doesn't have a speedo, but ... I reckon she (sorry he, his name is Edward) can cruise at 30 km/h and might do 40 km/h flat out. Steering at these speeds is a bit dodgy though. There's a lot of slack around dead centre so you tend to travel in a series of straight lines that converge more or less around where you want to go.