I just bought a 2007 Chevy Silverado with 37" tires. The speedometer has never been changed to read correctly with the over sized tires. Is there a way to do this without spending a couple hundred bucks on a programmer that I am only going to use once?

If I do have to buy a programmer, which is best?

Im sure someone on here has one. Im also sure places like 4 wheel parts, and maybe discount tire etc. would have the tool to let you do it.

You may be able to rent a scanner/programmer from an auto parts place that will do it. For most of the tool rentals, if you bring it back in good shape you get your money back.

A buddy and I did this with his F250 with oversize tires and a few engine mods. We rented the tool from O'Reilly's and did the speedometer calibration and some shift point adjustments in the parking lot and on the highway in front of the store. We told them what we were doing so they just sat on his credit card while we did the adjustments and rang up the rental/return when we were done. He asked about that, just out of curiosity, and the mgr said they have to show tool usage to justify having the loaner/rental program or corporate will yank it. It ended up being free.

Black bear performance is who you need to go with.

Has it been regeared or just lifted with tires?

Lifted with tires is all I know, but the guy I bought it from didn't have a clue cause all the work was done before he got it... I don't know how to tell just by looking...

If you have a smart phone download speed app. I downloaded speedview for my lifted Bronco to see how much I am off. Tested the application with my car and they matched in speed all the way to 85mph. You can get the computer reprogramed but its not cheap.

Is the speedo reading slower or faster than you're going?

If it's stock gears it's probably an absolute dog to drive with no power.

Blackbear is still the way to go. Custom in person tuning can't be beat u less you spend big money on efi live

Speedo is reading slower than the actual MPH.