Hope everyone is doing well. Just wanted to ask.

I got 35s put on my jeep. With 20 inch wheels.
I programmed with superchips and when I'm driving my speedo would read or example. If I'm going 80 my gps actually says im doing 74.

Any suggestions on how I can get speedo accurate. Should I change tire size on superchips to a bigger or lower size to compensate? Any suggestions would be great. Thanks.



My jeep

 

You didn't measure, just programmed it for 35" tires? If you grab a tape measure, you may find out that your tires are actually somewhere around 33.5" or so. Once you get an accurate size programmed in, then you can fine tune the height inputs if needed.

 

Ya just did it to 35s. I figured that's what I had to do.

So just measure from ground to
Top of tire?

 

Yep, start on a flat surface like a parking lot measure from the concrete to the peak of the tire which is the center most part so you will have to eyeball it some.

Any questions feel free to let me know.

Scott

 

you doing fine,,GPS always read 9% less than Odemeter and you will never get your speedo acuurate

if you try it in all cars its the same situation u getting.

there are some thread about acuurat GPS to Odemeter i think

 

Awesome. Thanks guys. I did measure it and reprogrammed.
It's now only 2km off. Which is good. Maybe if I program an inch less it
Will be right on.

 

Be sure to check it every month or 1000+ miles since the tread will wear down, so does the overall diameter of the tire... even if it decreases by .25 inch the speedo may be slightly off.

 

Awesome thanks!