Speedo Accuracy
Submitted: Monday, Jun 04, 2007 at 22:41
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46285
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Go-N-Grey (WA)
After years of experiencing optimistic speedos, I was shocked to discover of the WA long weekend the speedo in a stock standard LC 100 (V8 auto, 17" alloy wheels) actually undereads at 120km/hr, and is within 1 km hour (under) at most other slower speeds. Checked it with accurate GPS.
I normally sit on 120 km/hr when travelling from
Perth to
Bindoon and return each weekend (have done so for the last 15 years) in Pajero wagon, Commodore Wagon, Falcon Wagon, Forrester Wagon, and recently Toyota Prius. All are actually travelling at 115km/hr when the speedo indicated 120, so safe from speed cameras.
Not so with Tojo, I was wondering since I have had this vehicle why I was continually catching traffic ahead, and complaining at slow drivers. Actually doing 10k over the speed limit in WA means a certain speeding fine and with double demerit points - thats bad.
Any one else had similar experience?
Reply By: Member - joc45 (WA) - Tuesday, Jun 05, 2007 at 00:25
Tuesday, Jun 05, 2007 at 00:25
Not in a Tojo, but did get done in my mother's little Mazda 121, sitting on indicated 112 and got zapped for 120.
Gerry
AnswerID:
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Reply By: MP - Tuesday, Jun 05, 2007 at 06:24
Tuesday, Jun 05, 2007 at 06:24
Mate's new Hilux is out by 15%-GPS and other speedos(travelling at same speed in another vehicle) read 60km/h and his says 69km/h. Shouldn't get caught for speeding and it will be
well serviced considering it will have done less km's than actually shows on the odometer. Oh yeah, Toyota don't want to know about it, don't know how to fix it.
Cheers
MP
AnswerID:
244809
Follow Up By: Go-N-Grey (WA) - Tuesday, Jun 05, 2007 at 08:46
Tuesday, Jun 05, 2007 at 08:46
You should get very good fuel consumption figures also.........
I wonder however these days if the tyre sizes,diff ratios and all that is right whether it automatically also means the odo is also out by the same amount?
FollowupID:
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Follow Up By: dieselman - Tuesday, Jun 05, 2007 at 13:47
Tuesday, Jun 05, 2007 at 13:47
I drive a Ford Transit van for work and found my speedo to be 5-6km/hr higher than gps speed but the odometer is nearly 100% accurate? You would reckon if they could make odo 100% they could do the same with the speedo.
FollowupID:
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Reply By: Robin Miller - Tuesday, Jun 05, 2007 at 07:54
Tuesday, Jun 05, 2007 at 07:54
Hi Going
Grey
We seem to buy Rav4's regularly and our last 2 have been between spot on and under reading by 1kmh similsr to yours.
Surprised me a little to!
Robin Miller
AnswerID:
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Reply By: traveller2 - Tuesday, Jun 05, 2007 at 08:15
Tuesday, Jun 05, 2007 at 08:15
From memory the ADR's specify a 10% tolerance so you would have reason to complain to a manufacturer if the error was any greater.
In these days of electrically driven speedo's there should be no reason for error if it is straight from the factory.
Mind you if tyres are different from original, evenif they are the 'same' size but a different brand then there could be an error. Not hard to get a 10% error with just a tyre change.
AnswerID:
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Follow Up By: Mike Harding - Tuesday, Jun 05, 2007 at 09:09
Tuesday, Jun 05, 2007 at 09:09
ADRs require speedo to never read under true speed and to be accurate or over, by some percentage I cannot remember, at 40, 80 and 120kph.
Last time I did the trig. the difference between new and worn out tyres could account for about 3kph.
Most modern car's speedo's will be very accurate.
Mike Harding
FollowupID:
505914
Follow Up By: robak (QLD) - Tuesday, Jun 05, 2007 at 09:54
Tuesday, Jun 05, 2007 at 09:54
A reason for "error" can also be due to change in your tyre pressure and tread depth of your tyres.
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Reply By: deserter - Tuesday, Jun 05, 2007 at 10:21
Tuesday, Jun 05, 2007 at 10:21
In the last 12 months I have bought a new Hyundai Accent and new Prado. Both have factory tyres. Both read 96 on the GPS when the speedo reads 100. Same thing happened on my previous car - AU falcon.
AnswerID:
244848
Reply By: Outa Bounds - Tuesday, Jun 05, 2007 at 10:35
Tuesday, Jun 05, 2007 at 10:35
The same with our 80 Series, particularly after changing the engine, we thought it was a bit strange that everyone was driving slow on the trips between
Townsville &
Cairns, we discovered the speedo was close to 10k's out (via GPS like yourself) and shortly after got a fine in the mail.
Hubby managed to get some sort of new cable or something that corrects it to an extent, even still it's about 5ks out now, but at least we know & always drive 5k's below the speed limit
AnswerID:
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Reply By: Member - Terry G (NSW) - Tuesday, Jun 05, 2007 at 10:52
Tuesday, Jun 05, 2007 at 10:52
The ADR (18.5.1.1.2) actually allows a tolerance of +/- 10% for all speeds in excess of 40kph.
tg
AnswerID:
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Follow Up By: Mike Harding - Tuesday, Jun 05, 2007 at 11:05
Tuesday, Jun 05, 2007 at 11:05
Thanks for that Terry. Interesting. The reference you provide certainly does say as you suggest and all I can say is that, for sure, that is not how one major Australian vehicle manufacturer tests their speedos.
Looking at just one section of a standard can, sometimes, be misleading unless one understands all the other: "see sub clause 13.25a and Table 3 and note exceptions on days when the wind is from the northwest" :)
Mike Harding
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Reply By: Member - Brinic (WA) - Tuesday, Jun 05, 2007 at 13:11
Tuesday, Jun 05, 2007 at 13:11
Hi Go-N-
Grey,
We bought a 2007 Honda CRV Sport only a couple of months ago and that shows that I am sitting on 100km when my GPS states I am only sitting on 95. I brought this up with the dealer and I was advised this is how they are made and same as what everyone has said, it is also due to the tyres and pressure.
Can't see why to be honest, it had just come out of the factory. I had a Suzuki Liana previously with a digital dash and that was 100% accurate. A $25000 cheaper car is more accurate. hmmmm you have to ask.
I suppose at least you shouldn't get a speeding fine.
Nicole
AnswerID:
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Reply By: Kumunara (NT) - Tuesday, Jun 05, 2007 at 23:05
Tuesday, Jun 05, 2007 at 23:05
Go-N-
Grey
I drive one of those Toyota landcruisers at work. Have checked the speedo with my GPS and it is accurate.
If your speedo is out it is no defence to a speeding charge. A GPS is a handy little toy and could save you the embarressment and expense of a fine.
Tjilpi
AnswerID:
245032