...So, adding that onto an assumed built-in margin of error for the speed check, does that mean that at the point some people are caught doing 35 in a 30, their speedo's needle could show around the 40 mark..?
* as in, read on the internet without checking any facts against reputable sources
Yes, absolutely. You can always tell the people with satnavs when driving through motorway average speed check zones, because they're the ones *actually* doing 50mph (as indicated by the GPS) rather than the 45ish or so that people relying on traditional mechanical speedometers do.
Speedos that work mechanically by counting the wheel revolutions (and making assumptions about the circumference of the wheel & tyre) are always calibrated to under-read.
Yes, absolutely. You can always tell the people with satnavs when driving through motorway average speed check zones, because they're the ones *actually* doing 50mph (as indicated by the GPS) rather than the 45ish or so that people relying on traditional mechanical speedometers do.
Speedos that work mechanically by counting the wheel revolutions (and making assumptions about the circumference of the wheel & tyre) are always calibrated to under-read.
Newer more expensive cars tend to be better than old or cheap ones too.
My old peugeot under reads by quite a bit, but you can get a feeling where the actual spots are. I've clocked it on a straight road with the GPS so I know that for example when I get it up to 70 it indicates 120km/h etc :)
I'm hoping my Peugeot over reads a bit, after the other day when I passed two random speed checks within 5 minutes, doing 95km/h in an 80km/h zone in both cases...
Comments
Speedos that work mechanically by counting the wheel revolutions (and making assumptions about the circumference of the wheel & tyre) are always calibrated to under-read.
Newer more expensive cars tend to be better than old or cheap ones too.
My old peugeot under reads by quite a bit, but you can get a feeling where the actual spots are. I've clocked it on a straight road with the GPS so I know that for example when I get it up to 70 it indicates 120km/h etc :)
B
zx-diagnostics - Fixing ZX Spectrums in the 21st Century (wiki)
Sinclair FAQ Wiki