Can Nissan calibrate the speedo? I'm on stockers and it's off by ~3%. When I get new tires it will be off even more.8%F & 1.2%R). Will they correct this under warranty if they can do this? Also, is the speed obtained from the front or rear or both ends of the car?

 

http://www.miata.net/garage/tirecalc.html

Dont know if that helps. At my chevy dealership I work @ If they have not upgraded rims or tires we will cover it under warranty

 

A found a much nicer calculator here
http://www.rims-n-tires.com/rt_specs.jsp

Thanks about the chevy warranty, I suspect it's a computer thing that they just need to flash or something... Anyone else have their speedo calibrated?

 

the speedo is indexed by axle speed...so I can't see how it could be off at all

 

So you know if the speedo is indexed by the front or back wheels? I want to figure out what happens if you change the wheel size off the stock with different diameters for front and rear.

 

unless your Z is front wheel drive, I'd say its off the back wheels

go to any of the tire calulator sites and plug in the numbers, it will show you

 

thanks for the info, it makes perfect sense!!

 

I emailed the dealership here and they said the following:

So it will cost me to calibrate it or I can just deal with it. And from his reply it sounds like they just swap out speed sensors or something...??

 

From what I just read in the service manual, it gets the speed from the ABS actuator and electric control unit or VDC/TCS/ABS control unit. Seems you can test it for proper functionality but can not adjust it.