Speedometer Recalibration?

I just recently put a little bit bigger tires on my truck. Went from 265/75/r16 to 285s. My speedometer is off by about 3mph. Looking for some direction on how to get this fixed. TIA!

 

I think the rough country is your cheapest option

https://www.roughcountry.com/product/speedometer-calibrator-90043

 

Thanks! I’ll probably try this one out.

 

I also recently went from 265/75/16’s to 285/75/16’s. I have the Hypertech speedometer calibrator and it works well. I have read that it’s the same exact thing as the RC unit, just branded differently.

 

I am running stock tires and my speedometer is off by 2 mph, as measured by GPS on the recent 700 mile trip. I am living with it. Every car I've owned had speedometer off by 2, 3 mph.

 

Hypertech here too. I caught it on sale on the 'Zon. You may have to play with the settings though. I run 35's but have it set so it thinks its on 33's to get the speedo correct. Verified with 2 different GPS's as well. I'm within 1 mph.

 

get WAZE and forget about it

 

I installed the RC one. It works great, but you have to mess with the settings until you get close to an accurate reading.

 

does it mess up or play weird with the OTT tune? Or is it a completely separate thing altogether?

 

It’s a totally different thing. An ECU tune basically reprograms the shift points in the transmission. The speedometer calibrator tells the speedometer that your tires are a different size, essentially.

I have an old version of the KDMax tune and it all works just fine together.

 

Completely separate. It’s a hardware module that is installed behind your instrument cluster. Takes input from stock sensors on your truck, applies the changes you made when you programmed the module with your computer and sends the adjusted speed to your speedometer.

 

rad, thanks for that info