On Oct 15, 2011, at 4:10 PM, Jason Orr wrote:

> Can someone tell me if my speedometer is off much since I put 245 60 14
> tires on my stock rims? I wanted better handling and it definitely worked
> but I really didnt think about the mph difference. Thanks!!
At an indicated 65MPH, you're actually going 64.8004

I used this calculator:
http://www.paspeedo.com/calculator.htm
Old tire diameter=25.653543307086615
New tire diameter=25.5748031496063

bob ... I think one of the best means of doing this is to have a Scan Gauge
and using a GPS, drive at say, 70MPH, and see what the GPS says ....
it's the way I programmed my Scan Gauge, which I use as my speedometer.