Re-calibrating the speedometer?

I saw on the escape board, that when you buy new tires for a car, your suppose to get the speedometer re-calibrated. Is this true?

Only if you change tire size from OEM size. See tirerack.com as they have explained different tire sizes don't always mean the speedo is off, ie: 205/55/16 is similiar to 225/50/16. The aspect ratio to width determines overall diameter.<br>tireman

There is a wider tire that fits and is the same diameter, so no recalibration would be necessary. I put a set of 255/65-16 inplace of the 235/70-16 standard size that has a 3/4" wider tread but a negligible 0.3% theoretical difference in speed indication. At an indicated 100 MPH you would be actually doing 100.3 MPH assuming new tires with no wear. They fit fine but I would not recommend any wider tires than these unless get different rims since these clear some parts by less than 1/2". <br><br>Obviously if you are using the tires to help lower or raise the vehicle, you will have a large size variation. In this case , you will need to recalibrate the speedometer and probably have to have it verified to maintain the warranty coverage and get proper speedometer and odometer readings.

I belive they were referring to going from the 15" wheel/tire combo to the 16' package.