Is there a way to 're-calibrate' the speedo when changing the rear tire size? I was running 205/70/14 and just changed to 245/60/14's. I calculated a 1.1% difference, and if I am reading right, this makes the speedo read too slow (60 mph reading is actually 66). I don't like having that much difference.
I read on another post somewhere that something can be done, but can't find it and don't remember what to do. :dunce:
205/70-14 = 25.29 inches
245/60-14 = 25.57 inches
You ARE correct in the 1.1% difference, however the speedo reading would not be 6 MPH off but rather 0.6 MPH off.
I'm going to assume you have the stock speedo gear in the car that is meant to run with either 215/70-14's OR 225/60-15's
215/70-14 = 25.85 inches
225/60-15 = 25.62 inches
If ANYTHING you are reading on the high side(your speedo reads faster than you are actually going) and your choice in tire size has actually helped to make your speedo more accurate than the previous tires you had.
Sweeeeett !! It didn't 'feel' like it was off that much. I can only assume the gear ratio is stock as well. The lady I bought the car said it was her husband's "baby" before he passed away. I think he tinkered with a few things, but not sure. She said he was always took good care of it, but wasn't sure what he had done.
ANyway, thanks. I feel much better now.
Dave