Speedo Error Margin

[Towering]

nerdygril,

GPS is most accurate, esp the one that log on to more than 4 satellates.

It is used in many racing instruments to measure lap times. The ONLY down side of GPS is start up (detecting the exact moment of the car starts moving). So 0-100kmh testing is still measured by the ECU data.

Taka - What I cannot understand is why the Toyota GPS, in all models incl' my Sahara do not have "Speed as a display". My previous Holden Caprice did have this and it was very helpful, and I always drove by it

[Taka]

Taka - What I cannot understand is why the Toyota GPS, in all models incl' my Sahara do not have "Speed as a display". My previous Holden Caprice did have this and it was very helpful, and I always drove by it

Yes, that is the question I have too. It is software not hardware.... it may be a policy thing. Very annoying.

[slow_sam]

Could reporting a slower speed have something to do with better fuel useage? Even on the test track.

Just an idea.

[BlackAdder]

Could reporting a slower speed have something to do with better fuel useage? Even on the test track.

Just an idea.

G'Day there slow_sam,

No actually, reporting a slower speed would decrease your economy as you would not have travelled as far on the same amount of fuel, however, my Grande is doing the opposite, reporting a higher speed, and as a consequence, reporting a better economy than I'm achieving.

It's been covered somewhere else on this site that the ADR requirements are for manufacturers to calibrate their equipment at 0 to 4 kmph OVER actual speed, with a +10% tollerance on top of that, therefore if you were actually doing 100kmph, a speedo reading of between 100 to 114 is acceptable! I don't agree with it in any way shape or form, it sort of leads you to the impression of there being a big loop-hole if you were pulled up for speeding ... aka "But officer, the ADR says da da da and I was doing 114 on my speedo in the 100 zone, therefore I am within the stated tollerance!" I don't think it would work but it puts a big onus back onto the drivers.

AFAIK set the speedo to an accurate reading, give tyre suppliers access to a calibration module and have the speedo calibrated when you fit new tyres. That way, the speedo is correct and the onus is on the driver to drive within the laws of the road. Also, wear on the tyres will cause them to have a smaller circumference which will lead to the speedo showing an ever increasing (e.g. over actual) reading as the tyres wear.

Anyway, I have had my rant. Enjoy your driving and don't get too hung up on the finer details.

BlackAdder

[PaulG]

This is what I posted in the another post:

http://www.trafficlaw.com.au/speedos.html

Current Australian design rules (ADR) for cars built after July 2006 for speedos allow NO under-reading and over-reading of 10%+4km/hr. This means for a vehicle travelling at a true speed of 100km/hr, the speedo should read anywhere between 100-114km/hr. Vehicles built before this date had a +/-10% allowable error meaning the speedo could display 90-110km/hr for the same true speed.

So, I can now see why Toyota would set the speedo to over-read. The speedometer still has some error margin from manufacturer of up to +/-10% but most likely alot less, let's say +/-5%, so Toyota must set speedo to over-read by that error in order to comply with ADR.

Most likely all new cars regardless of manufacturers have this same policy because of the new ADR.

For the brave, I wonder if this gadget will fix the problem?

http://www.jaycar.com.au/productView.asp?I...=&SUBCATID=

[Taka]

Yes the ADR has too much allowance, No under call is a must because of the current police monitoring climate <_<.

Got one of these OBD scanner thingy

I am going to do a few 0-100 and I will do them slowly to match the GPS speed, so I can plot a graph.

[nerdygirl]

Got one of these OBD scanner thingy

I am going to do a few 0-100 and I will do them slowly to match the GPS speed, so I can plot a graph.

Cool will be really interesting to see the results.

[Taka]

I post something, which is very interesting and worth opening another thread.

http://au.toyotaownersclub.com/forums/inde...showtopic=16547

[klugerowner]

Hi have any of you thought about the way the speedo works? all car makers have been adjusting speedos up for years, The magnet in the speedo device wears out over time, and over the years the speedo become more and more inaccurate. Thats why older cars need more speedo calibration. If not tested and adjusted over the life of the car, and it reads 67kmph at 60kmph now, it ten years it may read exactly 60kmph and in 30years it may read 50kmph when you are doing 60kmph.

Car makers try to allow for this fade in the mechanism by adjusting up on delivery of a new car. I am assuming that speedo adjustment at each service is cost prohibitive, or there has not been strong customer demand for it.

As for the GPS, yes it can be out occasionally, I have tested several units in different parts of the world in cars and boats, GPS signals can be delayed and the units show the last available data and occasionally weather and sattelite postion can affect the read out too.. usually they are very accurate, but like any system they can have faults. I had two different GPS units reading two different speeds, that were both different to the Kluger speedo, and also different to the speed read out from the digital radar safety sign on the freeway, and slightly different from the manual timings we used for testing with stopwatches and road markers...

I guess it is better to be going a little slower than a little faster that you think when that blind corner comes up on you from out of nowhere.

[Kesawi]

I enquired with the Toyota service department about adjusting the speedo and they quoted me $500. Their reason was the instruments would need to be removed from the dash and sent away to a specialist. I decided that I'd drive to the GPS and save the $500 for other things.

[Kruzenvax]

Was driving late after dark couple of days ago... in an 80 zone, got 80 on a speedo but that was an end of a long downhill in the dark, cars all around me. And there was a pocket of darkness at the side of the road, spotted a police car with the radar there, straight after I passed it it took off and turned on lights, so I thought "there I have it", though I was doing 80. But the police car did not follow me, instead it and another car near me took the closest exit. So I thought "looks like I'm not having a ticket" and realised that a bit of a safety margin on a speedo is not such a bad thing!

[Taka]

Good post Kruzenvax it is so true.

[Kruzenvax]

Thanks Taka,

BTW, in Australia police cars don't write down the rego numbers to issue a ticket later, they chase to give a ticket?

I have also noticed that I subconsiously (sp?) learned "correct" needle positions for most used speeds (e.g. 110, 80, etc) so have no trouble with "true" 110 on a highway.

Edited April 29, 2009 by Kruzenvax

[Taka]

No they can't. Because:

I don't think so. I doubt retrospective infringement notice can stand much in court. There will be a serious judgement on the police officer and his memory. When a matter of IQ is put in court....... the matter will be dismissed.

Unless you think the police officer in the car has an IQ of 200. :P:

[Kruzenvax]

Thanks

[Mikeyboy]

I know the allowance over the limit, so I always use the GPS to make sure I am below it.

[RICE RACING]

nerdygril,

The ONLY down side of GPS is start up (detecting the exact moment of the car starts moving). So 0-100kmh testing is still measured by the ECU data.

:D Some of us have proper GPS scientific instruments :D

So 0-100kmh or 0 to 0.01kmh can be more accurately measured than by any other means :P

Rubbish toy type GPS units like in phones, Tom Tom's, Motec, Garmin, < LOL are NOT of scientific grade, thus they have gross errors of margin on very small measures and quick time scales (due to very low sample speeds *typically less than 10 Hz*). To give you an idea a high end 100Hz capable (100 individual independent measures of position per second) GPS engine costs $10,000 (just the electronic component alone).

Sorry to be picky but the internets is only really good for porn most of the time rather than sharing technical truth.

[57fritz]

No they can't. Because:

I don't think so. I doubt retrospective infringement notice can stand much in court. There will be a serious judgement on the police officer and his memory. When a matter of IQ is put in court....... the matter will be dismissed.

Unless you think the police officer in the car has an IQ of 200. :P:

Maybe not in Victoria, in NSW they have up to 28 days to issue a ticket!

[Crowdedhour]

After owning a 2004 Kluger CVX for 9 years I took delivery of my new 2013 Kluger KX-S last week (21/8/13). The 2004 model was always spot on in terms of speed accuracy (when checked against my various Garmin GPS' and those highway radar speed check displays one occasionally comes across).

The new Kluger, however, shows a speed discrepancy of 4 Kl per hour .. i.e. 110kph on the speedo shows as 106kph on the Garmin. Even at lower speeds the discrepancy is the same .. 60kph on the speedo shows as 56 on the Garmin and so on.

Its all very well to say this is within ADR tolerance rules and that there are benefits (e.g. avoidance of radar speed fines). It does not, however, necessarily make for safe and secure driving in certain situations.

Only yesterday in an attempt to get up some kilometres prior to the first complimentary service check I took to driving down the Hume Highway from Sydney to Moss Vale for lunch and on three occasions at different times, despite driving in the slow lane at the speedo indicated speed of 110kph, different semis/B doubles/ triples etc came up behind and tailgated, flashed lights, air-horned me and eventually overtook cutting me off dangerously pulling sharply in front after overtaking.

I was in the slow lane!! nowhere else to go. You just dont need it. Even though the Garmin was indicating a slower speed I did wonder if it was correct. Such doubts pass through the mind.

Yes .. I will be complaining at the first service but if one takes notice of other contributors to this topic, probably to no avail.

[trentmeyer23]

After owning a 2004 Kluger CVX for 9 years I took delivery of my new 2013 Kluger KX-S last week (21/8/13). The 2004 model was always spot on in terms of speed accuracy (when checked against my various Garmin GPS' and those highway radar speed check displays one occasionally comes across).

The new Kluger, however, shows a speed discrepancy of 4 Kl per hour .. i.e. 110kph on the speedo shows as 106kph on the Garmin. Even at lower speeds the discrepancy is the same .. 60kph on the speedo shows as 56 on the Garmin and so on.

Its all very well to say this is within ADR tolerance rules and that there are benefits (e.g. avoidance of radar speed fines). It does not, however, necessarily make for safe and secure driving in certain situations.

Only yesterday in an attempt to get up some kilometres prior to the first complimentary service check I took to driving down the Hume Highway from Sydney to Moss Vale for lunch and on three occasions at different times, despite driving in the slow lane at the speedo indicated speed of 110kph, different semis/B doubles/ triples etc came up behind and tailgated, flashed lights, air-horned me and eventually overtook cutting me off dangerously pulling sharply in front after overtaking.

I was in the slow lane!! nowhere else to go. You just dont need it. Even though the Garmin was indicating a slower speed I did wonder if it was correct. Such doubts pass through the mind.

Yes .. I will be complaining at the first service but if one takes notice of other contributors to this topic, probably to no avail.

You have got to be kidding me, this is the most petty form of complaining that I have witnessed in my years on this forum. Just deal with it, add 4kph to your indicated speed and accept that 95% of new cars have this 'error' built-in, intentionally!

Oh yeah, stop digging up old threads as well.

[Crowdedhour]

Sorry Trent. I do apologize. Don’t have the benefit of your years of experience on this forum so .. yes, I can understand your reaction to my apparent pin pricking and, as you put it, petty, comment. I had just come off the road all fired up. Should have known better.

Wasn’t aware though that it should be expected and is normal for speedos in new cars to be commonly and deliberately set at a lower speed. Not that having owned four Toyotas from new, including a Kluger, over the past 15 years would make me any sort of an expert (not one

of them had speedo error to the same extent as the one I have just purchased) nor the fact that my neighbour’s new Toyota does not have such a speedo error at all. My older Kluger from new always matched the Garmin speed even after tyre wear.

Digging up old thread?? A nice little finisher. Good one mate. Tell me, how on earth does one new to the arena know it is (apparently) bad form to continue a topical subject when the search engine actually takes you to the thread in question. I really didn't recognise that the subject had closed. So to all who are irritated and annoyed. Sorry.

Good that you are there to help us newbies along.

Edited August 30, 2013 by Crowdedhour

[trentmeyer23]

Now you are aware of all of the above, you're welcome.

[Andrew357]

Despite of Trent's... sharp response he is for the most part correct.

http://www.racq.com.au/motoring/cars/car_advice/car_fact_sheets/speedo_accuracy

You should feel blessed that your previous speedometers had read accurately given the rather wide range it has had legally to fall in. Your neighbour should give a rather large donation to the Motoring Gods for his current model reading true. If I were you, I would probably tithe your local Toyota Dealer a small amount for being -3.64% of your true speed. Let's face it; less than 5% error is pretty good.

In addition; while you're raging about angry truck drivers may I remind you that their aggressive; and from the sound of things unwarranted, boorish behaviour has nothing to do with your Kluger's speedo or your local Service Centre. I'd be noting their company, registration and time and lodging a formal complaint with their company. Most companies believe their drivers should display admirable qualities and driving of that behaviour would certainly be frowned upon as it reflects poorly upon themselves.

[Steven]

After owning a 2004 Kluger CVX for 9 years I took delivery of my new 2013 Kluger KX-S last week (21/8/13). The 2004 model was always spot on in terms of speed accuracy (when checked against my various Garmin GPS' and those highway radar speed check displays one occasionally comes across).

The new Kluger, however, shows a speed discrepancy of 4 Kl per hour .. i.e. 110kph on the speedo shows as 106kph on the Garmin. Even at lower speeds the discrepancy is the same .. 60kph on the speedo shows as 56 on the Garmin and so on.

Its all very well to say this is within ADR tolerance rules and that there are benefits (e.g. avoidance of radar speed fines). It does not, however, necessarily make for safe and secure driving in certain situations.

Only yesterday in an attempt to get up some kilometres prior to the first complimentary service check I took to driving down the Hume Highway from Sydney to Moss Vale for lunch and on three occasions at different times, despite driving in the slow lane at the speedo indicated speed of 110kph, different semis/B doubles/ triples etc came up behind and tailgated, flashed lights, air-horned me and eventually overtook cutting me off dangerously pulling sharply in front after overtaking.

I was in the slow lane!! nowhere else to go. You just dont need it. Even though the Garmin was indicating a slower speed I did wonder if it was correct. Such doubts pass through the mind.

Yes .. I will be complaining at the first service but if one takes notice of other contributors to this topic, probably to no avail.

Sorry Trent. I do apologize. Don’t have the benefit of your years of experience on this forum so .. yes, I can understand your reaction to my apparent pin pricking and, as you put it, petty, comment. I had just come off the road all fired up. Should have known better.

Wasn’t aware though that it should be expected and is normal for speedos in new cars to be commonly and deliberately set at a lower speed. Not that having owned four Toyotas from new, including a Kluger, over the past 15 years would make me any sort of an expert (not one

of them had speedo error to the same extent as the one I have just purchased) nor the fact that my neighbour’s new Toyota does not have such a speedo error at all. My older Kluger from new always matched the Garmin speed even after tyre wear.

Digging up old thread?? A nice little finisher. Good one mate. Tell me, how on earth does one new to the arena know it is (apparently) bad form to continue a topical subject when the search engine actually takes you to the thread in question. I really didn't recognise that the subject had closed. So to all who are irritated and annoyed. Sorry.

Good that you are there to help us newbies along.

Frankly mate, you need to accept that Toyota isn't to blame here. You're driving SLIGHTLY below the speed limit in the left hand lane and that truck driver was just being a tool. Long story short Toyota has done the correct thing by setting your speedo slightly slower (as all car makers do now). The fact is all modern tyres, even if they show the same tyre code, are not made exactly the same and some have a larger outside diameter than others. By setting your speedo lower, they're ensuring you don't inadvertently speed if you replace your tyres after they wear out and end up going slightly faster because of it.

You're whinging about nothing that has any credit here, and frankly by making the above the attitude you're bringing to this forum as it is don't expect a warm welcome - we tend to be quite blunt here and if you don't like it no one is forcing you to stay. People join this forum to contribute (ideally), and those that join just to whinge about nothing as treated exactly as above.

I don't know (or care) how old you are, but GROW UP

[Crowdedhour]

Thanks for your advice Steven. Appreciate your candour. Always good to share a view don't you think. Interesting what you mention about tyres and wear and their impact on speed error margin etc. All relevant.