Speedometer accuracy 482DervMan read what you put ? PUT ? ffs, if you're trying to communicate, try again. "if we spot a GPS unit on your dashboard " are you a police officer ? no...
They can believe whatever they want, it would be foolish to buttume that this is the case and rely on it.
For what it's worth, my 9-3's speedometer underreads by ~2 mph at all legal speeds (compared to the GPS reported speed). That doesn't mean I'll aim for 32 mph in a 30 limit.
Or rather to give it up, given the ruling on speedometers.
On a technical basis there is *no* leeway. 30 means 30. It doesn't mean 31 or 32. 70 means 70, not 74. Speedometers must either under read or be accurate. If you're caught doing 31 mph in a 30 limit then you must be aware that you were speeding. Is that "beyond reasonable doubt" - who knows. We didn't nick for one or two miles per hour over the limit, but 35 or so, yeah that's fair game.
The practicalities of the system and the sensitivities of the equipment mean that a gust of wind moving leaves, or whatever, can influence the accuracy hence camera are usually set to be several miles per hour over the limit. If you're caught at 37 in a 30 limit, chances are your speedometer is reading 40 or more.
Regardless, it's certainly possible to be nicked at 31 in a 30 limit. Harsh, perhaps, but possible.
-- The DervMan www.dervman.com
