The AUSubaru.com.au Forums

Hi There,

Just checked speedo in the new Outback against GPS, as it felt as though we were going slow. Turns out it is reading about 10% fast,

actual speed speedo reads

110 km/h 118 km/h
100 km/h 108 km/h
80 km/h 87 km/h
60 km/h 66 km/h
50 km/h 55 km/h

Any one else had issues? Is there going to be an easy fix?

In the big picture, it throws out all fuel economy calculations and we will also end up with a car that has 200,000 kms on that clock but it will have only done about 180,000 kms.

Thanks Phil

It has been like that since the Gen 3. Only way to fix it is to fit taller tyres. Work out the percentage ratio, then find out the OD of your tyres, at the percentage and then find a tyre with that OD.

I'm using a 225x70/16 and my speedo is now only 2% out but the other way now.

Use this Tyre Size Calculator

I have opposite problem with my 08 forester am fixing it with taller tyres.

Oops same problem. Am changing from 215/60 16 to 215/70 16.

Or install speedo corrector?
Cheers
AP

Hi AP,

What is involved in speedo corrector? Just got a response from Subaru Australia see below.
_________________________________________________________________

Thank you for your email to feedback at Subaru.

Regarding your concerns relating to speedometer accuracy, As per Australian Design Rule (ADR) 18/03 the maximum allowance for speedometer calibration is actual speed to a maximum of 'actual speed + 10% + 4km/h ' .

The reason this calibration standard exists is because the indication of the actual speed cannot be guaranteed. This is because of manufacturing tolerances of the speedometer and associated sensors, tyre wear and different option tyre types with slightly different rolling circumference.

The law states that the indicated speed must never be less than the actual speed and not more than 10% +4km/hr. Therefore due to the variables mentioned above the Subaru speedometer is calibrated to '
actual speed + 5% + 2km/h ' as being the mid point in the allowable range. This ensures compliance with the regulation and that you can be sure that your indicated speed is greater than the actual speed assuming correct operation of your speedometer.

With regards to odometer accuracy, the odometer and trip meters fitted to Subaru vehicles comply with ADR 18/03 also. However ADR 18/03 states that the odometer and trip meters must have an accuracy of 0 plus or minus 4%. Therefore any fuel economy calculations will have an accuracy of 0 plus or minus 4% and will not be calculated from the speedometer display.

Accordingly we are unable to recommend any modification to the Speedo to address your concerns.

Once again, thank you for writing to Subaru Australia.
_________________________________________________________________


This to me infers that calibration is possible to quite a high level of accuracy, so why not just make it correct? If it is a concern of someone claiming against them in the case of a speeding fine, make the customer sign a disclaimer if they want the calibration done.

If nothing else.....at least make it known that this is how they are set!!!

Phil

It will be correct only with the tyres it was calibrated in mind with/for. Changes in manufacturer tolerances or styles could change the acuracy. So many tyres out there designed for the one car. As we age a little we change our needs of tyres and our budget. Subaru have taken the middle of the road upper tolerance, I think? YEAH, surely in this day and age an annual vehicle inspection could check accuracy and be able to adjusted to EXACT, or on tyre change.

That +4kph bit on top of the 10% ,I did not know. Somehow I don't think Victoria's law enforcement don't either.

As far back as an MY with 175/70-13 speedo readings have displayed a speed faster than what actually travelling at. I fixed mine by fitting various 14 or 15 inch rims and tyres to be near enuff to sp[ot on with GPS

Diesel OB wrote:Hi AP,

What is involved in speedo corrector? Just got a response from Subaru Australia see below.

more than you want to play with on that car. spped is derived from the ABS system and then fed via CANbus to the speedo head.

do it with tyres - easier.

Ohh No!! CANbus has arrived at Subaru.....

Chris_Rogers wrote:more than you want to play with on that car. spped is derived from the ABS system and then fed via CANbus to the speedo head.

do it with tyres - easier.

The issue I have doing it with tyres, is that the signal is obviously split off separately to the speedo and odometer. Subaru state that the odometer is accurate as set out by the ADR's, which means changing tyres will screw my odometer taking with it all fuel calculations etc.

Seems as though I will just have to live with it and use the GPS and set cruise control until I can find and instrument company that thinks they have the gear to re-calibrate it.

It's easier just to live with it and when you setting cruise just compensate by adding 10% to your speed.

i think its interesting also, that speedo and trip meter are calibrated seperately.

They have the ability to put GPS in the vehicles at very little cost these days. Why they do not use a road speed and GPS reading to get an accurate speed is beyond me.

Buy yourself a gps, tomtom, navman or the likes if you want to drive at the exact speed and just put up with the speedo error.

Your speedo will change with tyre wear and the next time you fit new tyres. You can buy a listed 215x60/17 from a number of different tyre manufacturers and they will be a different OD.

Our brand new outback is the same. At 100kph on the speedo I am doing 9kph less. At 110 I am doing more than 10kph less.

Does anyone know of a company in Victoria that can recallibrate Subie speedos?

What is involved in callibrating, would it affect any other systems? On the face of it no as the odometer reads much more accurately that the speedo and the vehicle signal provides an accurate speed reading to.

I have had know luck and have had several contacts with Subaru and they won't have a bar of it. Several companies I have spoken with have said bit of a mine field to try and correct.

Still say it is a safety issue....just been on a long trip away and looking down at the GPS to set the cruise control to has whiskers on it, would be much easier if speedo was correct!!!

Hi there, your not alone with this issue, my Outback has the same problem.....

My car is the navigation version. So this means that the inbuilt satnav itself doesnt display my actual road speed. However my Tom tom satnav does. I only noticed the discrepancy in speedo display speed when I took along the Tom tom to use as a tool to warn me about traffic speed cameras positions.
The Tom tom was telling me accurate speed which was at 50mph showing about 46-7 on the Scoob's speedo.

Here we have average speed camera set ups ( popular on motorway roadworks) they are designed to keep the speed down over a long stretch (unlike fixed one shot cameras where you can slow down and then speed up again)
If you dont have then yet - heres what may come your way!
They read your number plate every time you pass an overhead camera -maybe a camera every mile or so and the system calculates your average speed travelled through the speed limited stretch. You will find out later in the post if you have been naughty!!

If I set my Outback to 50 on cruise through one of these average speed set ups, I get hasseled by the trucks, and other cars......very annoying, so I now know to set at 54 and that gives for 50 actual.

Renault now sells the Clio here, with Tom tom built in to the dash ! - I wont be buying one though just for that!

I am sure that this speedo discrepancy applies to other cars too, just gotta live with it!

Cheers
Giles

GPS lag is a current problem here. I have three separate systems in the work hack. They all lose the plot at same time. One is just my alerteGPS G220 worth a few boxes of cashews, but the other systems have had millions poured into them so need to be highly acurate and responsive - all lagging behind in speed, tracking. Thought it may have been in prep for Mr Obamas no longer impendining visit in June. Put off again due to oil leak crisis

I agree that other traffic is the largest concern with speedo errors.

Less than a week after receiving the Subi we were aggressively run off the Western Ring Road by a semi trailer because we were traveling at 100kmh on our speedo (somewhere about 90kph in reality).

Subaru will not accept this is a safety issue and I am frustrated that other peak bodies such as RACV do not see this as an issue either. In fact RACV refused to publish a readers comment I submitted regarding this speedo issue.

Road rage is an increasing problem and this type of stuffing around deliberately setting speedos to read incorrectly will only contribute to the error. I assert that one of the reasons road tolls are rising this year is due in part to this setting.

The other messgae that inadvertantly reaches the public is that Speeding is ESSENTIAL! In order to keep up with traffic one must ignoe the speedo in their car as it does not read the real (higher) speed.

Subaru were very testy when I suggested they must accept responsibility for loss injuriy from any road rage incident against us if we drive according to the equipment they have supplied.

However who else can take responsibility? The refuse to calibrate the speedos themselves, they threaten to cancel warranty and refuse to release algorithms to instrument companies. If this is not taking full responsibility then what is?

In all reality car companies have pulled off one of the biggest cons for the decade here by successfully lobbying UN and Governments to allow them to produce equipment with such huge built in errors.

funny cos my gen3 lib is dead on exact when compared to my tom tom. Like dead on exact.

alex