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Old 16th March 2019, 20:46   #11
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Originally Posted by Dorset Bob View Post
Yes, but in LittleMan's case, he is getting an under read whilst measuring distance.

Exactly. The time won't vary, but distance will vary directly as the speed. A speedo with a 10% under-read in speed means a 10% under estimate of distance. The quoted numbers for speed and distance don't vary exactly to theory, but it's in the right ballpark. Effects like tyres, pressures, etc. will also help to exaccerbate the error if they're not optimal.



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Old 16th March 2019, 22:14   #12
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Originally Posted by T-Cut View Post
Exactly. The time won't vary, but distance will vary directly as the speed. A speedo with a 10% under-read in speed means a 10% under estimate of distance. The quoted numbers for speed and distance don't vary exactly to theory, but it's in the right ballpark. Effects like tyres, pressures, etc. will also help to exaccerbate the error if they're not optimal.



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Iirc the Speedo runs on pulses from the and system as does the odo, however the speed over report is done in the software after the distance is logged.

However if you are missing pulses a short read is possible on the odo??

Question is is there an and light on and is it freaked so the op does not know...
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Old 16th March 2019, 23:57   #13
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Originally Posted by klarzy View Post
Iirc the Speedo runs on pulses from the ABS system as does the odo, however the speed over report is done in the software after the distance is logged.

However if you are missing pulses a short read is possible on the odo??

Question is is there an ABS light on and is it freaked so the op does not know...
I think your autocomplete spell checker evil tool doohickey has not learned that ABS is a thing these days?

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Old 17th March 2019, 11:56   #14
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However if you are missing pulses a short read is possible on the odo??

Dunno, but wouldn't the ABS system also respond?


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Old 17th March 2019, 12:48   #15
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Dunno, but wouldn't the ABS system also respond?


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Only at low speed when the gap in pulses is more noticeable
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Old 17th March 2019, 17:32   #16
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Only at low speed when the gap in pulses is more noticeable

I dunno. It depends on who/what does the noticing. The pulse frequency will vary every rev certainly, but why would the IPK respond but not the ABS when the same sensor is driving both? ABS can activate from braking at any speed, it only needs a variance in the four wheel pulse rates. It'll depend on the variance threshold I guess. Is the loss of a single reluctor segment likely? I dunno.



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Old 19th March 2019, 12:04   #17
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Solved!
Over the past week I have followed the odometer and used a phone app to measure the mileage done exactly.
First of all, google maps seems that is chosing a certain path, on which when I zoom in it just routes me on a longer path just before getting home. While driving, it changes the route to the shorter one I know. Never knew that, because I’ve always thought that’s the correct length.
Than, because of “new” car, I was excited to spend a little bit more time with it, so I’ve parked at the beginning of the street I usually park on. Never realised that I actually walked almost 1km to work, and that street is that long! )
Basically there were about 2 something kilometers missing from my commute. Which made perfect sense for the lower recorded mileage.

All is good, odo and trip distances are recorded fine, the problem was only my hawk eye to observe little insignifiant details like this

Gas mileage on the other hand is on the thirsty side, using more fuel by almost 2l/100km than either a Legacy with EJ253 or a Toyota with 1JZ on the same commute.
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