Alright. The new tires I'm getting will cause the speedo to be 2.3% slower, according to this:
Wheel-Tire - WWW.RIMSNTIRES.COM size comparer&sw1=185&ar1=70&bd1=14&rw1=6.5&et1=45&sw2= 195&ar2=70&bd2=14&rw2=6.5&et2=45&text1=&text2=
Can I use that percent, or will the odometer reading be changed by a different percent so I have to go a set distance and compare?