odometer inacurate with stock tires?
05-22-2007, 09:40 PM
#21
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Team N.V.S.
why would they do that ? why on earth would the ruin peoples resale values by putting in stuff to make inaccurate mileage numbers?
why wouldn't they recalibrate the ecu's output to make it correct. we do have a different ecu then tha world/japanese versions......
why wouldn't they recalibrate the ecu's output to make it correct. we do have a different ecu then tha world/japanese versions......
05-22-2007, 09:50 PM
#22
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It's not ruining anybody's resale values. For 100,000mi a 3% error is a difference of 3,000mi, less than an oil change interval. It underestimates anyway.
05-22-2007, 09:52 PM
#23
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i thought the stock bB wheels were 195/60/R15's and because our stocks are 185/60/R15, that's why they are off
05-22-2007, 09:54 PM
#24
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No stock bB tires are 185/65/15, making them slightly taller.
05-22-2007, 10:02 PM
#26
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whoops, my bad,
would a 195/60/15 compensate?
would a 195/60/15 compensate?
05-23-2007, 02:11 AM
#27
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It's the closest you can get in 195 width, yes.
05-23-2007, 07:44 PM
#28
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OK, something's wrong with this whole situation here...
A. If the bB came with a 185/65-15, and the xB comes with a 185/60-15, that means the original calibrations were for a taller tire than what we got here.
B. Given standard size tolerances between mfrs. and models, yes, that is a difference of approx. 3% between the two tires.
C. That means that our tires actually make more revolutions (per mile, etc.) compared to the original. In other words, they would be reading faster on the speedo (and hence, racking up miles faster on the odometer), not slower (as reflected on Tomas' chart). A taller tire would read slower
D. We should be multiplying by .97 (3% less) to compensate to correct speed, not 1.03 (3% faster/higher).
A. If the bB came with a 185/65-15, and the xB comes with a 185/60-15, that means the original calibrations were for a taller tire than what we got here.
B. Given standard size tolerances between mfrs. and models, yes, that is a difference of approx. 3% between the two tires.
C. That means that our tires actually make more revolutions (per mile, etc.) compared to the original. In other words, they would be reading faster on the speedo (and hence, racking up miles faster on the odometer), not slower (as reflected on Tomas' chart). A taller tire would read slower
D. We should be multiplying by .97 (3% less) to compensate to correct speed, not 1.03 (3% faster/higher).
05-23-2007, 08:42 PM
#29
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i believe what you just put is what tomas is saying. our ACTUAL speed is supposedly 3% slower than speedometer display speed.
I still think they recalibrated the input voltage to the speedo , and or correctly spaced out the numbers on the speedo to make up for the tire size difference.
I still think they recalibrated the input voltage to the speedo , and or correctly spaced out the numbers on the speedo to make up for the tire size difference.
05-23-2007, 08:46 PM
#30
With stock xB wheels/tires:
Multiply the indicated speed by ~0.97 to get actual.
Multiply the indicated distance traveled by ~1.03 to get actual.
The JDM odometer was calibrated in klicks, not miles, so that is a totally new translation in the software, and that translation is roughly 3% off in one direction. The JDM speedo had a different face, with klicks being the main measurement instead of miles, and the printed speedo face is off by about 3% in the OTHER direction.
The change in tire size for the US model happens to match, roughly, how far the speedo is off.
I don't know how many times or how many different ways I can say the very same information to try to get it through. I've resigned myself to knowing that not everyone will get it no matter how it is spelled out.
The odo and speedo are totally independent even though they use the same basic pulse input from the ECU as their electronic starting point.
Changing tires to make one right will make the other more wrong.
Just for laughs (S&G), here is information from two different pages in the same xB repair manual:
I'm going to lock this thread soon - it is just going around in circles and there are other threads that cover this very same information in excruciating detail.
Tom
Multiply the indicated speed by ~0.97 to get actual.
Multiply the indicated distance traveled by ~1.03 to get actual.
The JDM odometer was calibrated in klicks, not miles, so that is a totally new translation in the software, and that translation is roughly 3% off in one direction. The JDM speedo had a different face, with klicks being the main measurement instead of miles, and the printed speedo face is off by about 3% in the OTHER direction.
The change in tire size for the US model happens to match, roughly, how far the speedo is off.
I don't know how many times or how many different ways I can say the very same information to try to get it through. I've resigned myself to knowing that not everyone will get it no matter how it is spelled out.
The odo and speedo are totally independent even though they use the same basic pulse input from the ECU as their electronic starting point.
Changing tires to make one right will make the other more wrong.
Just for laughs (S&G), here is information from two different pages in the same xB repair manual:
I'm going to lock this thread soon - it is just going around in circles and there are other threads that cover this very same information in excruciating detail.
Tom
05-23-2007, 09:06 PM
#31
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so then tomas. which is right and which is wrong? the speedo right and odo wrong or odo right and speedo wrong ?
where is the proof.
the way I see it there is no proof either way.
but my car seems to be within 1mph of indicated at each and every radar traps i've gone through so i'll take that. and i've gone side by side with a buddy who has gpsand it was right but then again best way would be to have a digital lcd readout on the dash , lol
where is the proof.
the way I see it there is no proof either way.
but my car seems to be within 1mph of indicated at each and every radar traps i've gone through so i'll take that. and i've gone side by side with a buddy who has gpsand it was right but then again best way would be to have a digital lcd readout on the dash , lol
05-23-2007, 09:19 PM
#32
Remember that as econo-boxes there is a fair amount of potential 'slop' in how accurate each one is.
As to "which is right" READ THIS THREAD. It has been said numerous times that neither is expected to be correct, and they are off in different directions.
If yours is the magical box that is always right on with speed and distance measurements, great, but if it is, it doesn't meet the factory published specs.
What proof do you want? Drive a measured hundred miles and compare that with your odometer. Drive a measured mile and have someone with a stopwatch time it. THOSE are the proofs.
That's it. Enough. Thread locked.
Tom
As to "which is right" READ THIS THREAD. It has been said numerous times that neither is expected to be correct, and they are off in different directions.
If yours is the magical box that is always right on with speed and distance measurements, great, but if it is, it doesn't meet the factory published specs.
What proof do you want? Drive a measured hundred miles and compare that with your odometer. Drive a measured mile and have someone with a stopwatch time it. THOSE are the proofs.
That's it. Enough. Thread locked.
Tom
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