In a recent "tire thread" a comment was made about adjusting your speedometer to maintain accuracy with 205's.

Is this possible on a stock speedo? Does anyone have details?

You have to send it in to a speedo shop. Just drive it and figure its off by 10mph and you're fine.

Geoff

The different tire size changes the calibration. So what you can do is send it out to a speedo shop and have them recalibrate it for the tire size. Palo Alto or North Hollywood can do it.

Or you can do what I do, just figure the difference and compensate. The speedo in Betty's car is 6mph fast at 60 mph.

Contact Teri Davis. She has the rally procedures to calibrate a speedo. There is a measured course around TMS that can be used for speedo and odo corrections. It was used for the parade rally.

dont worry so much about the speedo If people are passing you ..you not going fast enough. Id be focusing on the TACH!

wow....

I think this maybe the first time that the advice from this board is "DO NOTHING"...woohoo

you guys rock!

Damn I musta been slacking for a moment. You could pull the speedo take it apart move the needle to 10mph and hole the shaft. pull of the needle and stick it back on at zero.

So that ought to screw things up pretty good. Or at least enough that you wished you left it alone.

that's perfect.....LMFAO

Every speedo i've ever had has been out of whack, ie never displayed the correct speed.
Apparently manufacturing tolerances for speedos are governed by legal requirments to be +0% but -10%. Which is meant to indicate your traveling slower than actual speed.

Buy or borrow a GPS unit & drive down a straight & level piece of road. Note your gear & rpm speed combinations.