Speedo Accuracy - which one is correct.

**EuroBro** · 11-10-2006 06:49 PM

I have my tomtom GPS on which shows the current travelling speed via satelite updating every second which was 7 kms/hr slower than the 100km/hr in-dash speedo reading.

I reckon honda has sped-up the needle to protect the service & warranty (7% is a huge margin)!

**TypeG** · 11-10-2006 07:00 PM

my tomtom appear to be the same as my speedo

**EuroDude** · 11-10-2006 07:25 PM

Yes the GPS is more accurate than the Euro's speedo, but its probably 1 or 2km/h off.

Car manufacturers rarely calibrate the correct speed, one reason is for safety. The Euro's typically go about 96km/h when the speedo shows 100km/h.

When I drove past one of those "you are going XXkm/h, SLOW DOWN!" road construction signs, it showed 63km/h when the speedo showed 68 or 69km/h

**mr_mojo02** · 11-10-2006 07:41 PM

also depends on ur gps. some will update quicker than others

**aaronng** · 11-10-2006 08:04 PM

Wheels tested both the base and luxury Euro 1 year apart and found that the actual speed was 96km/h when the speedo was indicating 100km/h.

**TypeG** · 11-10-2006 08:06 PM

must be something wrong with my car then coz i am surprise how accurate my GPS is
haha

**MiSloVic** · 11-10-2006 08:14 PM

the euro's speedo with 225/45R17 is quite accurate.. i've tried the radar speed detector along the melbourne end of Hume highway, set the cruise control at abt 100km/h and the speed indicated by the radar is 100km/h.

however.. when i tried the one along Geelong, at 100km/h, there is a difference of 4km/h.

**btchia** · 11-10-2006 08:54 PM

Originally Posted by MiSloVic

the euro's speedo with 225/45R17 is quite accurate.. i've tried the radar speed detector along the melbourne end of Hume highway, set the cruise control at abt 100km/h and the speed indicated by the radar is 100km/h.

however.. when i tried the one along Geelong, at 100km/h, there is a difference of 4km/h.

my euro with 225/45R17 is different detect on the albury to Melbourne radar speed detector, cruise at 120km/hr, radar indicated shown only 114km/hr, so not sure which is correct.....

**EuroAccord13** · 12-10-2006 12:49 AM

The other factor is that the speed is read as a digital and it has to convert to analog for the needle (This creates a 2-4% error)..

The needle reads 100km/h but my RSM reads 97Km/h

For those who has the RSM in the car, you'll see that the RSM speed is actually spot on and can be confirmed by driving through the speed radar... I know my RSM is accurate

..

**EuroBro** · 12-10-2006 07:48 AM

I just repeated my test and can confirm it is 96kms/h @ 100 - but still 4km/h adds up to 400kms/1000kms service intervals and a whopping 4,000k's more when I sell it @ 100,000k's.

**ZEi20T** · 12-10-2006 07:52 AM

dont forget those radars are also badly calibrated and MAY tell you a faster speed to get you to slow down

**EuroBro** · 12-10-2006 07:55 AM

Originally Posted by ZEi20T

dont forget those radars are also badly calibrated and MAY tell you a faster speed to get you to slow down

That's an excellent point - better to be safe than sorry. I reckon you could have a convincing case if you can prove that your speedo is slower using a GPS receiver.