i30 Owners Club

GOT PROBLEMS OR ISSUES? => GENERAL => Topic started by: WxmJax on December 14, 2014, 13:57:02

Title: Incorrect speedometer readings.
Post by: WxmJax on December 14, 2014, 13:57:02
Not sure which would be closer to actual speed but I was using my Nokia phone GPS sat nav and while that was reading 73mph the car's speedometer was saying 80mph.  Tyres haven't been changed (195/65/15) so can't factor that in.
Title: Re: Incorrect speedometer readings.
Post by: eye30 on December 14, 2014, 14:00:54
I'm sure Speedo's are set with a + tollerance of circa 10% so yours will be about right.

Title: Re: Incorrect speedometer readings.
Post by: CraigB on December 14, 2014, 14:09:06
There all set to read faster than what you are actually doing to keep you within the limits of the law but your's does appear to be further out than most I've seen "7mph ( 11kph ) difference".

At 100kph ( 62mph ) my vehicle is out about 3 to 4kph ( 2mph )
Title: Re: Incorrect speedometer readings.
Post by: Just Rick on December 14, 2014, 14:17:33
Sounds like You have one of the older FD poverty packs,or new GD active I think they call them,with the stock steel wheels,Cycril when I first bought him he was the same was actually 11kph slow,as it has been said all new cars since the ninties have been made with a safety buffer of up to 10 to 11 percent, but most are around the 5 percent mark
Title: Re: Incorrect speedometer readings.
Post by: WxmJax on December 14, 2014, 15:30:06
No, it's a 2012 GD 1.6 diesel blue active estate with alloys. Just been out now and it's reading (speedo/sat nav) 30/27, 40/36, 50/45, 60/54. Tyres are set at 32psi.

Now edited as I put the figures the wrong way around, the speedo was always the higher mph figure.
Title: Re: Incorrect speedometer readings.
Post by: Asterix on December 14, 2014, 16:56:44
Would be more fair if it was km/h..  :mrgreen:

All readings are 10% off so believe it's all legal, however not desirable.

It's probably a necessity to avoid a claim from the U.S. of A legal system. Can you believe the outrage it would be if an innocent American was speeding because the car wasn't showing fast enough.... :question:  :sweating:
Title: Re: Incorrect speedometer readings.
Post by: eye30 on December 14, 2014, 17:00:26
:link: What is the tolerance allowed by law for speedometer accuracy? in the uk? (https://answers.yahoo.com/question/index?qid=20121002120251AA3Uyzm)

 ACPO Guidelines on speeding, and the UK law regarding prosecution.

Vehicle construction and use regulations require a vehicle speedometer accuracy to be in the range of -0->+10%.

The implications are that it must never under-read - for obvious reasons - but may over-read.
Title: Re: Incorrect speedometer readings.
Post by: asathorny on December 14, 2014, 17:49:37
Not sure which would be closer to actual speed but I was using my Nokia phone GPS sat nav and while that was reading 73mph the car's speedometer was saying 80mph.  Tyres haven't been changed (195/65/15) so can't factor that in.

Yeah mine is similar, I can safely do 35'ish on the car speedo and know that I am not gonna be flashed by the speeding cam...   :goodjob: :goodjob: :goodjob:
Title: Re: Incorrect speedometer readings.
Post by: eye30 on December 14, 2014, 18:03:18
Not sure which would be closer to actual speed but I was using my Nokia phone GPS sat nav and while that was reading 73mph the car's speedometer was saying 80mph.  Tyres haven't been changed (195/65/15) so can't factor that in.

Yeah mine is similar, I can safely do 35 on the car speedo and know that I am not gonna be flashed by the speeding cam...   :goodjob: :goodjob: :goodjob:
Have you actually put this to the test by passing at 35 past a camera?

Title: Re: Incorrect speedometer readings.
Post by: asathorny on December 14, 2014, 18:30:14
Not sure which would be closer to actual speed but I was using my Nokia phone GPS sat nav and while that was reading 73mph the car's speedometer was saying 80mph.  Tyres haven't been changed (195/65/15) so can't factor that in.

Yeah mine is similar, I can safely do 35 on the car speedo and know that I am not gonna be flashed by the speeding cam...   :goodjob: :goodjob: :goodjob:
Have you actually put this to the test by passing at 35 past a camera?

Couple of times inadvertently, and thank heavens 'it's true'   :rofl: :rofl: :goodjob: :goodjob: :rofl: :rofl: :goodjob: :goodjob:
Title: Re: Incorrect speedometer readings.
Post by: eye30 on December 14, 2014, 19:23:06
Not sure which would be closer to actual speed but I was using my Nokia phone GPS sat nav and while that was reading 73mph the car's speedometer was saying 80mph.  Tyres haven't been changed (195/65/15) so can't factor that in.

Yeah mine is similar, I can safely do 35 on the car speedo and know that I am not gonna be flashed by the speeding cam...   :goodjob: :goodjob: :goodjob:
Have you actually put this to the test by passing at 35 past a camera?

Couple of times inadvertently, and thank heavens 'it's true'   :rofl: :rofl: :goodjob: :goodjob: :rofl: :rofl: :goodjob: :goodjob:
Next time you are over my way i'll take you past 3 new gatso camera's and you can see if these are set at 35 mph
Title: Re: Incorrect speedometer readings.
Post by: asathorny on December 14, 2014, 21:17:06
I never said that the CAMERAS where set at 35 Lester, what the hell have you been drinking  :Shocked: :Shocked: :Shocked: :Shocked: :Shocked:
Title: Re: Incorrect speedometer readings.
Post by: Shambles on December 14, 2014, 21:19:47
Quote from: asathorny
I never said that the CAMERAS where set at 35 Lester, what the hell have you been drinking

Maybe he's on speed :whistler:
Title: Re: Incorrect speedometer readings.
Post by: The Gonz on December 14, 2014, 21:23:05
To answer the original question, GPS readings are far more accurate.
:link: How accurate is a GPS-based speedometer? | GPS Systems (http://gpssystems.net/accurate-gpsbased-speedometer/)
Title: Re: Incorrect speedometer readings.
Post by: Phil №❶ on December 14, 2014, 21:26:52
As stated in every GPS manual, neither does the manufacturer of GPS devices guarantee their accuracy.

GPS works by receiving signals from up above and then (using a shortened form of Windows), performs calculations to determine all the information provided. There is a delay, so the readings are never going to be "real time". Due to distance, even the time is actually 4 to 5 hundred milliseconds late.

That said, GPS's are generally more accurate that a purpose designed, erroneous speedo. I've always hated this concept, the speedo should be deadly accurate and if you go over the limit, expect to get pinged IMO. I am quite capable of managing a car's speed.
Title: Re: Incorrect speedometer readings.
Post by: eye30 on December 14, 2014, 23:20:59
I never said that the CAMERAS where set at 35 Lester, what the hell have you been drinking  :Shocked: :Shocked: :Shocked: :Shocked: :Shocked:
The cameras are in 30mph zone so doing 35 should not activate them
Title: Re: Incorrect speedometer readings.
Post by: Phil №❶ on December 14, 2014, 23:56:06
Last time I checked, 35 was greater than 30.  :Shocked: :mrgreen:
Title: Re: Incorrect speedometer readings.
Post by: eye30 on December 15, 2014, 00:20:23
Last time I checked, 35 was greater than 30.  :Shocked: :mrgreen:
Correct.

But if asa is right then doing 35 in a 30 zone should not activate the camera as within non activation tollerance.

I,e

30 plus 10% plus 2 = 35
Title: Re: Incorrect speedometer readings.
Post by: Phil №❶ on December 15, 2014, 00:25:38
O I C,

I assumed 35 actual, not 35 indicated, silly me.  :-[
Title: Re: Incorrect speedometer readings.
Post by: mjt57 on December 15, 2014, 02:27:35
No, it's a 2012 GD 1.6 diesel blue active estate with alloys. Just been out now and it's reading (sat nav/speedo) 30/27, 40/36, 50/45, 60/54. Tyres are set at 32psi.

Did you post correct figures here? GPS is reading higher than the speedo in the above figures. The OP had the speedo reading higher.

I have a 2011 (last of that shape with a CRDi 6sp manual) and 17" wheels. According to the TomTom the speedo reads 100 km/h at 98 km/h GPS indicated.

There's a local road with a road-side speed indication. It corresponds with the GPS. 62 km/h indicated for a speedo reading of 60 km/h.

So, it's not out by much, perhaps a needle thickness. But yours seems to have a lot more error.

Being all electronic can they be re-calibrated?

Some motorbikes can have a thing called a 'speedo healer' fitted which corrects errors. Wonder if there is the same for cars.
Title: Re: Incorrect speedometer readings.
Post by: asathorny on December 15, 2014, 09:59:39
Last time I checked, 35 was greater than 30.  :Shocked: :mrgreen:
Correct.

But if asa is right then doing 35 in a 30 zone should not activate the camera as within non activation tollerance.

I,e

30 plus 10% plus 2 = 35

Your exactitude should be a standard to which we all aspire   :goodjob: :goodjob: :goodjob:   Once we learn how to spell tolerance of course  :rofl: :rofl: :rofl: :rofl:
Title: Re: Incorrect speedometer readings.
Post by: eye30 on December 15, 2014, 12:28:22
Last time I checked, 35 was greater than 30.  :Shocked: :mrgreen:
Correct.

But if asa is right then doing 35 in a 30 zone should not activate the camera as within non activation tollerance.

I,e

30 plus 10% plus 2 = 35

Your exactitude should be a standard to which we all aspire   :goodjob: :goodjob: :goodjob:   Once we learn how to spell tolerance of course  :rofl: :rofl: :rofl: :rofl:

:rofl: :rofl:
Spelt that way as you have to pay, a toll, to come through the mersey tunnel.....unless you are a cheap skate and use the M53 and M56 and add miles to your trip....
Title: Re: Incorrect speedometer readings.
Post by: asathorny on December 15, 2014, 14:51:30
You know very well that I am a cheap skate Lester, I thought it was a club requirement? 

56 every time for me, the only time I came through the tunnel a bloomin lorry turned over and I was two hours late AAAggghhhh.

If I incur tolls or indeed any other travel costs it goes on the invoice  :goodjob:  Which I guess means, tax payer funded, YOU Lester, you help to pay my travel Yiiippppppppppeeeeeeeeeeeeeeeeeeeeeee    :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl:
Title: Re: Incorrect speedometer readings.
Post by: asathorny on December 15, 2014, 14:54:13
also I am hoping to be back in your neck of the woods bout springtime, so just behave yourself or I shall have you banned from cycling round Heswall millionaires row  :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :mrgreen: :mrgreen: :mrgreen: :mrgreen:
Title: Re: Incorrect speedometer readings.
Post by: diablo on December 15, 2014, 15:16:40
Last time I checked, 35 was greater than 30.  :Shocked: :mrgreen:
Correct.

But if asa is right then doing 35 in a 30 zone should not activate the camera as within non activation tollerance.

I,e

30 plus 10% plus 2 = 35

That's about right. I got a speeding ticket a couple of years ago for doing 36 in a 30 zone.  It said on the info on the back that they only prosecute if ii is above 35.

I checked my speedo against GPS a while back and it wasn't far out at all. That probably explains why when I'm following some cars through 30 mph Gatsos they slow down to 27. It is probably showing as 30 on their speedos.
Title: Re: Incorrect speedometer readings.
Post by: Lorian on December 15, 2014, 16:27:27
I've had a ticket for doing 34 in a 30. £60 fine and 3 points at the time. about 8-10 years ago. hand held gun. If i'd have know about 10%+2 at the time I would have maybe challenged it.
Title: Re: Incorrect speedometer readings.
Post by: Asterix on December 15, 2014, 17:05:58

Being all electronic can they be re-calibrated?


On a VW if you have the VCDS computer you can adjust the accuracy of the speedometer, so maybe possible on a Hy as well.... :question:
Title: Re: Incorrect speedometer readings.
Post by: Mike SX on December 15, 2014, 17:37:44
The cameras are in 30mph zone so doing 35 should not activate them

This Police Officer WAS only doing 35mph in a 30 Zone  :whistler:
:link: Policeman Anthony Rees-Thompson who switched number plates to avoid fine is jailed | Daily Mail Online (http://www.dailymail.co.uk/news/article-2874638/Undercover-policeman-switched-number-plates-Vauxhall-Corsa-bid-avoid-60-fine-doing-35mph-30-zone-jailed.html)
Title: Re: Incorrect speedometer readings.
Post by: Johnno on December 16, 2014, 03:28:46
I think its better to have it over reading by 10% +2, gives you a bit of lea way,
Title: Re: Incorrect speedometer readings.
Post by: The Gonz on December 16, 2014, 04:27:01
I have no problem with mine underreading. I drive 5-10 under the limit anyway. :goodjob:
Title: Re: Incorrect speedometer readings.
Post by: Dazzler on December 16, 2014, 07:48:25
I have no problem with mine underreading. I drive 5-10 under the limit anyway. :goodjob:

At those speeds wouldn't you be more of a Squadron Follower?  :whistler:
Title: Re: Incorrect speedometer readings.
Post by: Shambles on December 16, 2014, 08:06:30
^  good one :laughter:
Title: Re: Incorrect speedometer readings.
Post by: The Gonz on December 16, 2014, 08:41:31
 :rolleyes:

Dazzd jokes again? :head_butt:
Title: Re: Incorrect speedometer readings.
Post by: Surferdude on December 16, 2014, 09:11:13
I have no problem with mine underreading. I drive 5-10 under the limit anyway. :goodjob:

Note to self.

Avoid getting stuck behind GONZ 63 on the highway.  :whistler:
Title: Re: Incorrect speedometer readings.
Post by: diablo on December 19, 2014, 04:06:35
I have no problem with mine underreading. I drive 5-10 under the limit anyway. :goodjob:

Note to self.

Avoid getting stuck behind GONZ 63 on the highway.  :whistler:


Ditto, though rather unlikely. I wondered who these old dodderers were.  :D
Title: Re: Incorrect speedometer readings.
Post by: WxmJax on December 22, 2014, 17:33:24
Sorry people, sat nav reading should be the LOWER figure and the speedo the Higher.  :fum: 
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