Speedometers that read high

It's illegal for the speedo to read slow...( ADR requirement ) so I guess all speedo's will read fast....just depends on make and model and how fast they read !! ( they are allowed up to 10% )

This is not a new thing....been going on for years !!

The rule is a bit complicated but I think at 100kph real speed they are allowed to read anywhere from 100 to 114. I'll see if I can find the reference for this...

Up until mid 2006 the ADRs required speedos to be within a range of +/- 10% - so could read high or low.

In 2006 the ADRs changed and now speedos must be within a range of 0% to 10% - so must read from accurate to 10% high - no under reads are permitted.

Garry

As the tyres wear the speedo reading will be slightly less also

Regards Don

you were told wrong--------------------------------- its been the case for many years

pic up any old wheels mag and the vehicle tests would have the speedo error listed

Thanks for all the reply's, I now have all the ADR rules on speedometers. Passenger cars commercial vehicles, trucks + 6 Km/h Motor bikes +8 Km/h Mopeds + 4 Km/h Rule apply from 1 July 2006. It appears this is an international rule.

Yes you are all correct with your assumption that speedos must read fast. BUT - what's the real problem. If you travel in a 100 km/ph zone with your speedo on 100 km/ph and in reality the speed you are travelling at is say 97 km/ph then you WON'T get pinged for speeding. Too many people are in the habit of travelling at say 3 - 5 km/ph over the limit in the misbelief that authorities allow that much. RUBBISH 60 is 60 and 100 is exactly that 100. Most states have now lowered their 'tolerance' and in some states it is 1 - 2 km/ph. You've been warned.

everyone eeds to remember that if you get done for speeding
the excuse of speedo reading wrong is not a defence . its up to you to beware of it .
mechpete

I have a 08 turbo diesel hilux , speedo is consistantly 10% slower than GPS at all speds.
I have a 89 HJ61 landcruiser, speedo is spot on as GPS to 80 kph and about 3 kphout to 140kph. Maybe the digital readout can be programed as the manufacture wants., old mechanical cable, gearing, what can't be programed can't lie. .... Love the old 61.

Interesting
I have 4 that I use the GPS in
1987 MWB Toyota Jap import, farm truck
!997 Ford Explorer bought in NZ
2005 F250 built in USA
2008 Toyota Troopy bought in Australia
They all consistantly read 8% low on the speedo compared with the GPS.
Set the cruise control at 108 speedo = 100 GPS
Perhaps my Magellan 700 is reading wrong
Cheers
Russ

My 76 series speedo reads faster than it is actually going as well at 100ks via the GPS but is spot on at 60ks.