speedo correction

[emac]

so being a dull grey old day i decided to experiment on my WK2

the original tyres were 30" in DIA and the present tyres are 29" DIA

giving me a speedo error or 3 kmph so if the speedo is indication 100 kmph

the car is really doing 97 kmph. so no big deal, some would say a nice safety margin.

but it also upsets the distance travelled on the trip meter and the indicated fuel economy

so using JScan i reprogrammed the tyre DIA, followed the steps and sure enough i got an ABS error light, so followed the Adaptive procedure for the ABS "module" and it clicked and clunked and reset its self

run tested it with a seperate GPS and speedo now reads accurate

hmm time for a drink.

[drover]

I thought about it but then with a couple of near misses with a speed camera and no ticket, all I could put it down to was the speedo error saved my wallet.

[Jeeper6]

I recalibrated the tyre diameter on mine too when I fitted these new tyres a while back...originals were 30" but currently 32". Got the same ABS error, followed the same procedure and all good since...the indicated speed compared to a GPS is still a tad out though...but near enough...

[emac]

yeah i hear what you are saying drover, ill certainly be having to pay more attention.

actually i was chasing the reset procedure for my NAG1 trans, even with an Idrive
i was starting to get really annoyed with it, always changing up to early in normal day to day driving.

however, and the jury is still out, but it seems to have improved , i have the Idrive set to U3 or U4,

where i live there is a modest incline coming into the estate and now it seems happy to drop to second as i turn in and then hold third up the incline, whereas it would get into fourth when want to kick back to third

so i was running through the setting i came across the tyre diameter setting and thought what the heck

its a seat of the pants thing but it seems that what would appear a modest change has made a difference, and don't forget with a pentastar any improvement is noticeable ( not like you diesel drivers haha with all that torque)

[drover]

I can't remember the procedure to clear memory on the NAG 1, one of those key, peddle dances I think, someone is bound to chime in with it though.

Makes sense though getting the tyre size right would adjust the rev/speed settings for a few things.