Speedometer Calibration Help!

[seniorjumper82]

Hey everyone. Just had truck leveled today with 2" level kit and BFG KO2 275/60/20 tires put on. Have hyper tech calibrator coming in tomorrow so my question is that with this being my 3rd truck I've leveled and added tires my speedometer on this one is like 30mph off from GPS. All my others have been 3-5mph off and they had larger tires. Any suggestions or thoughts would be appreciated. Thanks in advance.

 

Jason

[b1gted]

Not sure what you are asking. My thoughts are to take the hypertech calibrator that you ordered and calibrate the speedo based on new wheel/tire size. :-)

 

 

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[seniorjumper82]

Normally the trucks I leveled and added tires before calibration was only 3-5mph from gps. This one is almost 30mph difference between gps. And yes it's on mph and not km.

[JRL1164]

Normally the trucks I leveled and added tires before calibration was only 3-5mph from gps. This one is almost 30mph difference between gps. And yes it's on mph and not km.

I believe you but that can't be right. I went to a 33" in 18 and was 3 fast. I feel like something can't be right. Be anyways calculate your tire height with a tape measure. According to BFG my tires are 33.2 but measured is 32.5 and that's what I had to go with to get my speed accurate again. Are you using your phone? Try using another app.

[seniorjumper82]

I've used 2 different apps. I was wondering if I just unhooked the negative battery terminal for a minute if that might reset it somehow. Sorry not very mechanically inclined.

[seniorjumper82]

Well I feel like a moron. I of course had my phone plugged in charging and listening to the music off my phone and soon as I unplugged the phone the gps speedometer app was only off 1-2mph. Sorry for the rant! note to self... Don't use gps app when phone plugged into USB port.