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Post by Roadsterstu on Apr 26, 2017 21:13:46 GMT
I'm sorry if I came across as judgemental, that wasn't the intention. I was referring to people fearing they would be fined at 1mph over the limit. I certainly don't think 67 is really excessive in a 60. Hopefully the camera van read a slightly lower speed anyway but I think you'll be OK as you are below the 10% +2 "guidance".
I definitely don't think you deserve it!
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Post by Alex on Apr 27, 2017 7:52:11 GMT
I'm sorry if I came across as judgemental, that wasn't the intention. I was referring to people fearing they would be fined at 1mph over the limit. I certainly don't think 67 is really excessive in a 60. Hopefully the camera van read a slightly lower speed anyway but I think you'll be OK as you are below the 10% +2 "guidance". I definitely don't think you deserve it! In your professional opinion you should! |
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Post by Big Blue on Apr 27, 2017 8:51:26 GMT
Indicated 67 should be a corrected 63.7. The manufacturer over-speed is pretty much 5% across the board.
The speeding fine I recent received in the post from Sardinia last summer gives a very nice breakdown of the speed limit, the allowed amount over the limit and the calculation of the speed I was charged with doing based on the allowance and some percentages.
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Post by Tim on Apr 27, 2017 9:03:54 GMT
I think that before these are rigidly enforced they need to sort out the speedo variations. With the proliferation of these signs that now flash up your speed I've noticed quite a variation between the cars at, say, 30mph.
That's based on going through the same speed zone on the same day which should remove any timing/accuracy variables
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Post by Martin on Apr 27, 2017 14:42:22 GMT
The BMW isn't a set % different, it is 3mph under at 50, 60 and 70mph. The Fiesta I had last week was reading 140kmh when it was doing a GPS 130kmh.
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Post by Boxer6 on Apr 27, 2017 17:37:39 GMT
The speedo on mine is, I think right on the 10% limit of acceptability for error, at least according to the satnav (both inbuilt AND Garmin's finest) readings. It reads 66mph at a 'true' 60 and I'm travelling at 73mph at an indicated 80. Pretty poor really, I reckon, but it does reduce "The Fear" a bit when spotting a traffic car/scamera van and realising I'm (probably) all right!
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Post by LandieMark on Apr 27, 2017 19:08:25 GMT
Speedos have to be within 10% at 30mph. Most over read. I found the Legacy speedo was 10% over across the range. The Volvo and the Mercedes were 3mph over regardless of speed. The Defender (running the ancient system of a speedo cable driven by a gear in the transfer box) reads spot on at all speeds.   |
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Post by johnc on Apr 27, 2017 19:11:57 GMT
My car is 2mph over at all speeds but my wife's Audi is within 1mph over
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Post by Boxer6 on Apr 27, 2017 19:31:04 GMT
It does make me wonder why, if some can get the speedo essentially bob-on, why can't they all? It can't be that hard to do for crying out loud!
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Post by Roadsterstu on Apr 28, 2017 8:53:50 GMT
I think that before these are rigidly enforced they need to sort out the speedo variations. With the proliferation of these signs that now flash up your speed I've noticed quite a variation between the cars at, say, 30mph. That's based on going through the same speed zone on the same day which should remove any timing/accuracy variables I will say it again, these will not be rigidly enforced as in 1 or 2mph over. That is simply because of speedometer inaccuracies. Other factors such as tyre diameter can effect gearing and thus speedometer accuracy. As already stated, they can legally over read by up to 10%. Mine is around 7% at 70mph. I checked at work and was directed to the force website where they have the same table CB posted. Note that it is only guidance but any force enforcing more rigidly simply makes a lot more work for itself and the fines go to central government, not police forces anyway, so it isn't self-funding. |
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Post by Roadsterstu on Apr 28, 2017 8:56:33 GMT
It does make me wonder why, if some can get the speedo essentially bob-on, why can't they all? It can't be that hard to do for crying out loud! Our marked Astras don't have calibrated speedometers (like traffic cars do) but they are absolutely bang on with my satnav all the time. I don't think they are a special police spec so maybe Vauxhall managed to nail it. |
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Post by Alex on Apr 28, 2017 19:50:11 GMT
It does make me wonder why, if some can get the speedo essentially bob-on, why can't they all? It can't be that hard to do for crying out loud! Our marked Astras don't have calibrated speedometers (like traffic cars do) but they are absolutely bang on with my satnav all the time. I don't think they are a special police spec so maybe Vauxhall managed to nail it. I thought it was a cost issue. The more accurate any form of measuring equipment is the more it costs to produce. Thus it would probably cost 10x as much to build in a speedometer that's bang accurate then to have them supplied with an accuracy of 7-10%. |
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Post by Roadsterstu on Apr 30, 2017 8:35:57 GMT
May be a cost issue, may be a design issue. It could be that the Astra has range-wide technology that, on the boggo spec models is still used but only for the speedometer, whereas further up the range it links in with navigation, safety systems, etc. It could also be interrogated after a collision for speed and other data, maybe.
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