what devices are you guys out there with lifted trucks/bigger tires using to correct your speedos?

Matt

 

you can get your dealer to recalibrate for larger tire sizes and they can get it pretty darn close. From what I hear within 3mph. Im sure theyll get closer with time.
As far as a tuner goes pretty much all of them recalibrate for tire size.
SCT is the way to go

 

I'm surprised how close the speedo is with my OEM 20's. I have a new Garmin Nuvi nav system which shows your speed real time and the speed is nearly spot on. My regular cars are mostly German and they always run several mph fast...

 

At the risk of sounding like Captain Obvious, The wheel size can change without it affecting your speed if the overall wheel/tire diameter doesn't change. You can have an 18" wheel with a taller sidewall tire vs. a 20" wheel with a lower profile tire, and the ycan bth have close to the same overall diameter.

 

dealer can only calibrate between the OEM tire sizes...ie I can switch a superduty with 18" wheel configurtions to the calibration of a superduty that has 20". This will help in some instances and that is what we have been doing but we have a lot of trucks running around with 37" and 40" rubber and there is not enough play in factory settings to get the speedo close.

Yes the majority of tuners can calibrate for tire size but I know SCT for sure is only releasing base programs and not doing any custom calibrations such as tire size etc right now...it's coming, but its not available yet.

 

If you dont want to spend alot of money on a tuner, Superchips sells a programmer to adjust the speedo for larger tires. I think it's around 250.00 or 300.00 dollars. I think it will raise the top speed cut out to.