Speedometer calibration?

[TRX_450]

ok so i took my 05 silverado to the local dealership today to get my leveling kit and tires put on it. i went from a 265 to a 315 and i told them to make sure they calibrated my speedo. i went to pick it up and the guy says its 4mph off and they tried more than once to fix it but the computer in my truck wouldnt allow anything bigger. has anyone ever heard of this? im thinking of buying a calibration thing myself and doing it.

[jesseweaver]

i know a lot of chips will calibrate for tire changes and such. i just 3.73 gear put in my stang, and the speedos off like 6-7- mph. it reads fast so it also puts more miles on the car, so im gettin a chip asap.

[rollie]

yeah theres a computer you can buy that recalibrates it, i believe its called a respeed, but its lke $300, my truck is off 10% so when it reads 60 im doing 66

[300ex_#387]

What size tires do you have Rollie? When mine says i'm going 55 im actually going 63 and thats with 35's. I don't feel like paying $300 though lol.

[Titanium]

315 and 265 are your width of your tire. whats your tire height?

[quad9]

dealer can only program a factory size. if it was available with that size, as an option then you will be ok.

[Titanium]

Originally posted by quad9
dealer can only program a factory size. if it was available with that size, as an option then you will be ok.

he can also fix his speedo by lowering his gearing.

[rollie]

Originally posted by 300ex_#387
What size tires do you have Rollie? When mine says i'm going 55 im actually going 63 and thats with 35's. I don't feel like paying $300 though lol.

i have 35's too but with a tape measure there more like 33's:confused:

[Titanium]

Originally posted by rollie
i have 35's too but with a tape measure there more like 33's:confused:

that happens pretty often. it varies between tire manufacturer. for example most of mickey thompsons 35's are actually 34" tires. its pretty goofy if you ask me:rolleyes: