Speedometer Correction after installing 07 Tahoe 20's

[GeoffP]

Hi all,

I just installed a set of 07-08 pull off 20's from a new Tahoe on my 02 Tahoe. 245/75-16's to 275/55-20's. The tire ratio calculators I've found online says I can expect my speedometer to read low by about 4 percent (about 3 MPH). While it's not a huge deal for me, it could be to my wife because she has a lead foot and pushes the "envelope" a bit. What's the cheapest place to get the PCM reprogrammed for the new tire size? I'm guessing the stealership isn't the best place to get this done. Does anyone know if the newer SnapOn diag tools can do speedo corrections?

Thanks in advance!
GeoffP

 

[greengumby]

Hi all,

I just installed a set of 07-08 pull off 20's from a new Tahoe on my 02 Tahoe. 245/75-16's to 275/55-20's. The tire ratio calculators I've found online says I can expect my speedometer to read low by about 4 percent (about 3 MPH). While it's not a huge deal for me, it could be to my wife because she has a lead foot and pushes the "envelope" a bit. What's the cheapest place to get the PCM reprogrammed for the new tire size? I'm guessing the stealership isn't the best place to get this done. Does anyone know if the newer SnapOn diag tools can do speedo corrections?

Thanks in advance!
GeoffP

any1 that does pcm tunes and most performance programmers can do the job . Or borrow one someone that may have one the new snap on diag tool may be able too ..

 

[Yuke2K]

The stealership actually shouldn't be that bad...we did this on my wifes explorer a while back, let me see if I can find the service ticket...


If you go in there and tell them exactly what you need, they probably wouldn't charge more than $40-$50 for the reprogramming since theres no diagnostic BS involved. They just have to plug in, change a parameter in the ECM, and unplug. But then again, that's money you could throw toward a black bear tune or other mods, so I feel your pain lol.