Speedometer with 20's

[buddyleee5]

How much isthe speedometer off with 20" rims on the car? ist here any way to adjust it so that the speed is correct? what is the normal differnce between the speedometer and the actual speed with rims?

 

[Palmguy]

The only thing that matters is the tire diameter, so that's the first thing that you need to figure out, not the wheel diameter. You could have the same size wheel with a tiny tire or a huge tire and that would make a huge difference in the speedo reading with the same wheel.

 

[Quik LS]

http://www.1010tires.com/TireSizeCalculator.asp

compare you new ones to the stock

 

[T_Man]

And an SCT Xcal2 can adjust the PCM and correct the difference.

 

[02LSE96LSC91SE84TC]

My 20s seem to be more accurate than the stockers, only about 2mph freeway speeds difference. 245/35/20 IIRC