2012 D-Max speedo accuracy?

A bit of reading.

From 1 July 2006 newly introduced models of a vehicle available on the market must comply with ADR 18/03. Also, from 1 July 2007 any newly manufactured vehicle (excluding mopeds) must comply with this rule.

This new rule requires that the speedo 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 more than 10 percent plus 4 km/h. Significantly, this change means that speedos must always read 'safe', meaning that the vehicle's true speed must not be higher than the speed indicated by the speedo.

That is, at a true vehicle speed of 100km/h the speedo must read between 100km/h and 114km/h. An alternative way to look at it is; at an indicated speed of 100km/h, the vehicle's true speed must be between 87.3 km/h and 100km/h.

Significantly, this change means that speedos must always read ‘safe’, meaning that they are not permitted to read lower than the actual speed of the vehicle.

Better still, forget the GPS, the speedo is 8kmh over so if you sit on 100kmh by the speedo you are using your cars built in insurance.

So Just go by the speedo. Tony Abbott does and he isn't going over the limit..

I should say I own a Colorado.

Aussi Traveller

Speedos don't record kilometres travelled only the odometer does.
So the ODOMETER will possibly register near correct distance as it isn't locked in any way to the over set amount the speedo has built into it.
So 10,000km reading will be close to 10,000km travelled depending on tyre wear or tyre size change of course.

Fitting larger tyres ie 265/75/16 may make the actual road speed be near or same as the speedo reading but it will tip the odmeter reading to be less than accurate.
ie. ODO reads 9200km when really travelled 10,000km ( using your figure here)

Doesn't matter what vehicle you own the principles are the same.

Ross M

Most if not all speedos nowadays are driven electronically from the onboard computer.(ECU)

I have an Isuzu NPR truck that was 9klms out when I bought it, I complained on the first service and let the service guy know, he said the usual that all speedos can be up to 10% out !

True but then I said well if its so far out then the onboard fuel use monitor and all other computer derived items, cruise control etc. are also out.

He said he'd get the Tech to re flash the ECI, which he did, and now my speedo is spot on with my GPS.

Yes it can easily be corrected but its just a case of convincing them to do it !

I am aware that the Isuzu/Colorado has an electronic speedo. It's signal is sent from a gear driven sensor mounted on the transmission extension housing.
What I was referring too, is that whilst my speed registered fast, the distance measured was very close to correct, unlike a reply posted earlier.

Hazo
The cruise control only reads a stream of pulses and holds that setting when the cruise is set by you, therefore the cruise has no real bearing on the speed of the vehcile as it is only set to what you want and doesn't rely on a needle position on the dash.
The speedo and the cruise just happen to use the same pulse source to read or perform the the cruise setting.
Fuel calcs shouldn't be affected because they are using the distance aspect of the info and not a speedo speed .

All the reflash did was eliminate the insurance speed which was originaly set into it so you didn't get booked as easily.

Ross M

MarJac
Also until recently was on second Mercedes Atego truck travelling highways to Vic and SA its speedo was out only half a Kim and always passed cars when limit was 100klm so that might explain some of the consternation with trucks supposedly speeding/passing cars

KYLE S
A GPS will tell you the speed if you are walking and at that speed it has the maximum time to read all the reference data and give you a reading which is as accurate as you can get.

If travelling at 1000km/h they are a little off compared with the GPS system in the aeroplane I was flying in at the time.

All data calculated by a GPS is used to determine altitude, speed direction etc and while they have some tolerance they are fairly close to true when speed is calculated.

I have 5 different types of GPS based units and all are extremely close re speed. Within 0.5km/h.

As I mentioned slower is more better.

Gidday Kyle,

The GPS speed is accurate in a straight line. When you're turning you will get a slight error (you will appear to slow down, according to the GPS).

KYKE S

Be careful.
Don't travel too far to the left you might be invited to join a certain political party.