I'm not sure what standard this refers to, but I dug up this article I remember reading previously (it doesn't appear to be published on the site anymore)

The applicable standard for many vehicles sold in NZ is a European standard that specifies that speedometers must not indicate a speed less than the vehicle’s true speed, or a speed greater than the vehicle’s true speed by an amount of more than 10 percent plus 4 km/h.

If true, that means a speedo is considered legally accurate if it says 114 when you're driving 100, which is a pretty massive difference.

Bigger tyres is a nice workaround, both our cars over read by 4kph so I just do the maths.

[–] Ilovethebomb@lemmy.nz 2 points 2 weeks ago (1 children)

A speedometer that far out is effectively useless, and if I bought a vehicle like that I'd take it up with the dealer.

So yes, Seymour might not have even been speeding.

[–] absGeekNZ@lemmy.nz 3 points 2 weeks ago (1 children)

This is one of my pet peeves; this is not the 1950's; we can make speedometers accurate to within 3%....this margin would account for all the vagaries of tire pressure etc.

Our newest car; pleasantly has a very accurate speedo...

[–] Ilovethebomb@lemmy.nz 1 points 2 weeks ago

Modern vehicles have GPS calibrated speedometers, and are often dead on. But for an electronic speedo, there's no excuse for more than a few percent.