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#3391253 - 06/07/14 05:09 AM Android My Tracks speedometer calibration
Gokhan Offline


Registered: 12/29/10
Posts: 1547
Loc: Los Angeles, California
If you have an Android phone and preferably also some dash or window mount, you can use the Android My Tracks app to calibrate your speedometer. Just record the track and display the stats, which shows the speed. This said, the following are my calibration results, which are typical for Toyota cars with analog speedometers. They overindicate the speed for safety reasons. Note that in addition to My Tracks, some GPS devices also show the vehicle speed, perhaps not as accurate as My Tracks.

Code:
Actual vehicle speed    Speedometer speed

35 MPH                  38 MPH
45 MPH                  48 MPH
55 MPH                  59 MPH
65 MPH                  70 MPH
75 MPH                  80 MPH
_________________________
1985 Toyota Corolla LE, 4A-LC engine, ~ 257,000 M
Toyota (by ExxonMobil) SN/GF-5 0W-20 Synthetic
Toyota 90915-YZZF2 filter, 90430-12031 drain gasket

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#3391331 - 06/07/14 08:50 AM Re: Android My Tracks speedometer calibration [Re: Gokhan]
kyxtremetuber Offline


Registered: 07/29/13
Posts: 46
Loc: Kentucky
They don't over indicate for safety reasons it to get the car out our warranty faster
_________________________
2012 Ford Fusion
2.5L Duratech 40000mi
0-30000 Motorcaft 5w-20 Full Syn 30000- Kendall GT1 FL910s
2000 Ford Excursion 6.8L Triton 150000


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#3391357 - 06/07/14 09:36 AM Re: Android My Tracks speedometer calibration [Re: Gokhan]
Vikas Offline


Registered: 07/22/05
Posts: 8101
Loc: NorthEast
Almost all cars over indicate by 3-5% One can easily confirm that with a GPS although an Android application can make it lot easier.

Of course, whether indicated speed on the speedometer matches the reading obtained from the vehicle speed sensor i.e. OBD-II VSS PID, is completely different matter!

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#3391388 - 06/07/14 10:41 AM Re: Android My Tracks speedometer calibration [Re: Gokhan]
lugNutz Offline


Registered: 05/19/13
Posts: 407
Loc: Somewhere in IL
A couple years after I bought my '06 Altima, there were some complaints filed somehow, due to the speed being off by 2+ MPH from the factory. Nissan allowed you to bring in your car for free recalibration.

That being said, speed being off by a percentage is common now. I wonder why Nissan allowed it to be recalibrated back then, but no automakers are doing anything about it these days.
_________________________
'05 Ford Explorer XLT | 96k | WIX 51372 | FS 5w-30

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#3391417 - 06/07/14 11:45 AM Re: Android My Tracks speedometer calibration [Re: Gokhan]
wrcsixeight Offline


Registered: 10/15/10
Posts: 1028
Loc: california
I went from a 235/75/15XL(stock size) to a 30x9.5x15 tire a 3.9% increase in diameter,

And now my Speedo, according to gps, is right on the money.

So far that has been the only time I have used the GPS on my smartphone, though once, I did notice my battery draining faster and noticed it was turned on. Not sure how that happened.

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#3391452 - 06/07/14 12:35 PM Re: Android My Tracks speedometer calibration [Re: kyxtremetuber]
gfh77665 Offline


Registered: 09/01/08
Posts: 2288
Loc: Southeast Texas
Originally Posted By: kyxtremetuber
They don't over indicate for safety reasons it to get the car out our warranty faster


Thats absolutly correct. Honda intentially did this, and had to settle with the Gov't for doing so. They over calibrated their speedos 3%-5%.

Anyone who thinks its "for safety" is fooling themselves.

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#3391460 - 06/07/14 12:50 PM Re: Android My Tracks speedometer calibration [Re: gfh77665]
Gokhan Offline


Registered: 12/29/10
Posts: 1547
Loc: Los Angeles, California
Originally Posted By: gfh77665
Originally Posted By: kyxtremetuber
They don't over indicate for safety reasons it to get the car out our warranty faster


Thats absolutly correct. Honda intentially did this, and had to settle with the Gov't for doing so. They over calibrated their speedos 3%-5%.

Anyone who thinks its "for safety" is fooling themselves.

This is actually simply false. Speedometer and odometer have entirely different calibrations, as they have independent mechanisms. Odometer is a mechanical counter, whereas the speedometer is some sort of a magnetic or spring torsion balance.

For example, in my case, the odometer overindicates by only about 2%, while the speedometer overindicates by about 7 - 8%. Speedometer calibration is for safety reasons.
_________________________
1985 Toyota Corolla LE, 4A-LC engine, ~ 257,000 M
Toyota (by ExxonMobil) SN/GF-5 0W-20 Synthetic
Toyota 90915-YZZF2 filter, 90430-12031 drain gasket

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#3391600 - 06/07/14 05:15 PM Re: Android My Tracks speedometer calibration [Re: Gokhan]
gfh77665 Offline


Registered: 09/01/08
Posts: 2288
Loc: Southeast Texas
Originally Posted By: Gokhan

This is actually simply false. ...

, the odometer overindicates by only about 2%, while the speedometer overindicates by about 7 - 8%. Speedometer calibration is for safety reasons.


Really? Let me provide something to back up what I said:

http://www.cbsnews.com/news/is-your-odometer-cheating-you/

In a class action lawsuit, Holmes charged Honda with fraud, claiming the company actually designed their odometers to run too fast.

"It shortened the warrantees, it shortened the lease contracts, it increased the lease mileage penalties that customers pay and as a result, Honda was able to generate and save millions of dollars," Holmes said.


Thats one of many, many articles available that proves it was about WARRANTYS, not "safety".

If most all speedo's were off 8%, don't you think people would be able to tell, and most would be complaining about it?

http://www.foxnews.com/leisure/2012/05/11/how-fast-are-really-going-accuracy-speedometers/

This says BY LAW, they have to be +/- 2.5%, thats no where near the bogus 8% you claim.

Do your home work before trying to call me out.


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#3391724 - 06/07/14 07:48 PM Re: Android My Tracks speedometer calibration [Re: gfh77665]
Gokhan Offline


Registered: 12/29/10
Posts: 1547
Loc: Los Angeles, California
Originally Posted By: gfh77665
Originally Posted By: Gokhan

This is actually simply false. ...

, the odometer overindicates by only about 2%, while the speedometer overindicates by about 7 - 8%. Speedometer calibration is for safety reasons.


Really? Let me provide something to back up what I said:

http://www.cbsnews.com/news/is-your-odometer-cheating-you/

In a class action lawsuit, Holmes charged Honda with fraud, claiming the company actually designed their odometers to run too fast.

"It shortened the warrantees, it shortened the lease contracts, it increased the lease mileage penalties that customers pay and as a result, Honda was able to generate and save millions of dollars," Holmes said.


Thats one of many, many articles available that proves it was about WARRANTYS, not "safety".

If most all speedo's were off 8%, don't you think people would be able to tell, and most would be complaining about it?

http://www.foxnews.com/leisure/2012/05/11/how-fast-are-really-going-accuracy-speedometers/

This says BY LAW, they have to be +/- 2.5%, thats no where near the bogus 8% you claim.

Do your home work before trying to call me out.

Actually, you aren't well-informed about this.

Here is the standard speedometer calibration from the official OEM repair manual for the 1985 Toyota Corolla. As you see, the minimum standard overindication for the speedometer is +4%, and the standard overindication range is anywhere between +4% to +8% and +4% to +15%, depending on the speed. I believe this is also the case for even the newer Toyota's. Odometer is a different story:

_________________________
1985 Toyota Corolla LE, 4A-LC engine, ~ 257,000 M
Toyota (by ExxonMobil) SN/GF-5 0W-20 Synthetic
Toyota 90915-YZZF2 filter, 90430-12031 drain gasket

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#3392193 - 06/08/14 01:23 PM Re: Android My Tracks speedometer calibration [Re: Gokhan]
Boxnuts Offline


Registered: 12/31/13
Posts: 17
Loc: England

There different rules in different parts of the world. In the UK I believe that the basic rule is that the speedo shall never read less than actual. So to allow for errors the speedo has to set to about 5% fast as standard.

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#3393732 - 06/10/14 07:51 AM Re: Android My Tracks speedometer calibration [Re: Gokhan]
hsd Offline


Registered: 09/05/09
Posts: 219
Loc: NE
Besides the lease, warranty, safety issues the erroneous speedometers make the gas mileage look better than it really is.

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#3394095 - 06/10/14 03:26 PM Re: Android My Tracks speedometer calibration [Re: Gokhan]
1 FMF Offline


Registered: 08/12/02
Posts: 1505
Loc: CT
Gokhan consider your source of information... it's coming from the manufacturer who is the one cheating the customer.
you're also referring all the way back to 1985, when i assume is using mechanical stuff.
from year 2000 till now it's all electronic based off the vehicle speed sensor (VSS) in the tail shaft of the transmission. That rpm, along with rear axle ratio if applicable, and tire size = speed and distance. There is no excuse if it is off by 1% or more, the only thing that would affect it is tire wear which is negligible. my 2005 altima was 4 mph fast on the speedometer at 50mph and above, but accurate at 30mph and below. accuracy based on a digital signal does not change like that, unless programmed purposely in the computer! i also verfied on straight highway i always drive, my 05 altima showed higher mileage for a given distance vs my 2002 camaro. and it always seemed like i was getting to 3000 or 5000 miles pretty quick and time for another oil change, which is what led me to looking into it.

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#3394224 - 06/10/14 06:44 PM Re: Android My Tracks speedometer calibration [Re: Gokhan]
Garak Offline


Registered: 12/05/09
Posts: 11347
Loc: Regina, Saskatchewan, Canada
Originally Posted By: Gokhan
This is actually simply false. Speedometer and odometer have entirely different calibrations, as they have independent mechanisms. Odometer is a mechanical counter, whereas the speedometer is some sort of a magnetic or spring torsion balance.

Exactly. My speedometer on my G is about 10% faster than the real speed, which I tested by radar. However, the odometer is quite on the money when it comes to odometer test strips on the road. In fact, using a ScanGauge, I can see the difference in its reported speed verses the speedometer. And, if resetting the average speed indicator while driving at a steady state, I get the proper speed shown there.

I can't speak for your vehicle, and I haven't checked out the F-150. However, Infiniti/Nissan is obviously not trying to "cheat" anyone out of warranty miles. I wouldn't call "safety" the issue either. They don't want people groaning to them when they get a speeding ticket. wink
_________________________
Plain, simple Garak.

2008 Infiniti G37 coupe - Mobil Delvac 1 ESP 5w-40, Hastings LF113
1984 F-150 4.9L six - Quaker State GB 10w-30, Wix 51515

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