Speedo adjustment

I'm planning in the new year to put a lift and bigger tyres on my D40 and aware that this throws the speedo etc out. With the on board giving on going fuel consumption figures etc was wondering if it is possible to get the computer adjusted for the new wheel size so that the speedo and other information are still correct.

I had a speedohealer on my bike because of me changing gearing and needed the correction. I believe it works on cars also, if not there are similar ones out there for cars. Easy with the electronic speedos.

Just about every electronics place (Jaycar DSE Altronics etc) make speedo adjusters. You'd be hard pressed getting Nissan to adjust the ECU even at a cost I'd imagine. The cheapest method is to still use a GPS, if you don't like looking at a GPS for speed data just use it for a few days and each time you look at your speed look at your tacho and learn to drive by the tacho. Most speed adjusters are money you don't need to spend.

KraftyPg said:

J You'd be hard pressed getting Nissan to adjust the ECU even at a cost I'd imagine.

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^yes.......NO THEY WONT....Thats a fact.

I wonder if they'd do it for a fee. There is probably no one who can afford the fee but I'd be interested to see if they could make a quick couple of hundred would they do it or is editing the ECU beyond the abilities of most knob jockeys at Nissan dealerships.

ScanGauce2 will help, you can calibrate the speed on it with the gps to get it spot on accurate. My nav when has factory tyres on, the speedo was 8 kmh too fast. Now I have 275/70 and the speedo is not only 3 kmh fast but I use scangauge to monitor the speedo as its spot on because It has been calibrated with GPS. Also scangauge can tell litres/100 and a lot more things. Google scangauge up. Cheers

Nissan won't do it. Even when necessary by law. The dealer was looking for a private firm to do the recalibration. The cluster is set at the place of manufacter and Nissan won't touch em

Sure they wont touch it if it's within the ADR, no manufacturer/dealership would do more than they have to just to keep a customer happy, but they can't refuse to to fix it or have it fixed if it's outside the ADR and under warranty.

What I don't know is whether dealerships can fix it for a price or if it has to go outside to somewhere else.

The dealer can't do it. It has to go outside. The speedo reading is actually not where the ADR 18/03 rule wants it and also the ADR/law also allows the consumer to request that the manufacturer to make the speedo show true speed. This is fact

The basic way it was explained to me by my legal person is that the owner can request it changed by the dealer but the dealer does not have to change anything unless it's outside what is a legally allowable "error". If they refuse to change it when it falls outside the legally allowable error matters can be taken further.

It's not the dealerships or the manufacturers who decide what the error is allowed to be so it's hardly surprising they don't want to do something for nothing that they aren't required to do. I doubt any business in this world would in a similar position.

That's not to say that for a price a dealer can't have it changed, some of them will do anything for a few extra dollars, especially dollars they can earn by someone else doing the work.

YBOD said:

I'm planning in the new year to put a lift and bigger tyres on my D40 and aware that this throws the speedo etc out. With the on board giving on going fuel consumption figures etc was wondering if it is possible to get the computer adjusted for the new wheel size so that the speedo and other information are still correct.

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You need something like this http://m.jaycar.com.au/m_productView.asp?ID=KC5435

Cheers fellas, it is very frustrating that it can't be done not because its not technically possible but instead because Nissan can't be ar$ed. I may have to find a computer geek somewhere, kidnap his teddy bear and refuse to return it until he hacks my can and fixes it ;0)

Had seen the scanguage but would have preferred to adjust the existing gauges rather than fit a new box to the dash.......although perhaps that isn't possible.

Gggggrrrrr it does seem that no matter which country I've lived in (UK, UAE and here) Nissan are famed for their lack of helpfulness.

Depending how big the tyres are do u need a speedo adjustment. From factory they are a certain percent down. I had 265/75:16s (32's) put on and the GPS speed is now accurate with the speedo.

My info is not from a legal member but it is straight from Canberra...the government agency that is the ADR and (transport and infrastructure mob)
They have told me personally and with regards the my 08 D22 that as a consumer I can demand that Nissan make my speedo read true speed and how the ADR 18/03 is interpreted.

There is a thread on here allready on the very subject. I still have all the emails between myself, Nissan and the infrastructure mob..

Now if many people make a noise the more chance Nissan themselves will do something quicker tho I tried to start a revolution back then but no one cared....we just get the same topic pop up every month or so.

Demand only if it doesn't fit into the ADR otherwise it's a request they can refuse. But you are right there is another thread, there is also shitloads about it on the net including the legal precedence if one looks hard enough and it basically comes down to after market fixes if it's within the ADR and legal fights if it's outside and refused.

KraftyPg said:

Demand only if it doesn't fit into the ADR

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No. That's not what they told me or wrote me

If the speedos were totally outside the adr...there would be a recall

And yes there is truckloads of threads on the internet about this subject...but if one can't believe the agency that makes the rules (where I got my info from)
then what point is there

I would NOT buy anything to adjust the speedo, because of the way the Nissan ECU works out the speed of the vehicle.

In days gone by it used to be mechanical. They moved it to a gearbox output shaft sensor and when traction control/ABS entered the picture, they changed again - speed is now calculated as a 'best average' of the inputs of the ABS. In the newer vehicles, they also use this same average information to determine if one wheel is spinning faster (that's the TCS).

The ECU (on standard tyres) knows fairly accurately what speed the vehicle is doing. What's NOT accurate is the needle deflection - and that's what has to be calibrated if it's not displaying as per ADR. I've found that the ECU is quite accurate with the actual road speed (compared to GPS) - it's just a crap needle.

If you change tyre size then you'd need to adjust the ECU's figure for tyre circumference. This may or may not cause the inaccurate needle to look more accurate.

If you want to push to have it properly calibrated you can, but to be completely accurate you should have the ECU reprogrammed. I think there's a mob in the UK that do it - you have to pull your ECU out, mail it to them and wait for a few weeks.

Makes the GPS solution seem so much easier eh?

Yes...atm a GPS is the best solution.


As a side note I find that via the OBD interface I get a true speed reading from the ecu.