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Discussion Starter #1
After buying larger "taller" tires, How do I correct the posted speed on the speedometer? I am not planning to buy an electronic tuner & monitor. Thanks
 

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cumminsforum.com
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You can use a programmer like Smarty or SuperChips to correct the tire error.

Or like my case I used my ScanGauge II to get corrected miles and MPH reading from the ECM/PCM. My truck has stock sized tires (265/75 R16) but I'm still off by 0.5 MPH on the speedometer and odometer. But The ScanGauge II reports the true speed and distance...

Or you can do it by hand by calculation...
Tire size calculator
 

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Rescue Tower
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Only option is to take it to a dealer to get updated.
 

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Discussion Starter #4
Ok Thanks for the information. I checked out the tire size calculator, good stuff. I am currently running 265/75/16, so when I get some bigger tires I'll probably take it to a speed shop or the dealer and get the necessary adjustments. I'm probably over cautious concerning the IP and tuners.
 

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Rescue Tower
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They have to flash your computer... not sure a speed shop can do that.
 

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It is not a flash.just a calibration change in the abs module
 

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Discussion Starter #7
what does the term "flash the computer" amount to?
 

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what does the term "flash the computer" amount to?
That would be removing software and replacing it with different version..................
 

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It is not a program change............
 
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