Callibrating Speedometer for 285 nitto tires

[Brian Teitell]

So i have tt/shackle lift and now have 285/75/16 tires. I am pretty my speedometer is about 7 mph's off. I feel like it says i'm going 70 when i am at least going 75. I went to the Stillwater Ford Dealership and they said they could not recallibrate it. Could my local Dallas dealer do it, since they probably have better tools? If so what do they do and how much would it be, I'm in college and pretty poor hehe!!!!

Thanks,

Brian

 

[Richard L]

It's not a matter of better tools. The speedometer/odometer adjustment is made in the ECU which all dealers should have a programmer. The problem may be that your tire size has created an error to large to correct. Usually the can only adjust for a maximum of 5%. But they may just not want to do it.



New vehicles don't use the conventional speedometer gear in the transmission, they use a digital speed sensor. I don't know if they are adjustable or if they can use a different speed sensor.



Perhaps someone who has an XCal can tell you if it has a Speedo adjustment setting??



...Rich

 

[Keith Lewis]

With the Xcal2, the tune has an option for a specific number of revolutions per mile (the most accurate method to do it) and the tuner can set that for you.

 

[Johnny O]

I just allow that I'm going 10% faster than the speedometer says. My method has the advantage of being free.