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K Madigan
08-06-2009, 07:42 PM
Now that I have put on the new 16" wheels, I can anticipate that my speedometer would be off a bit. One website looked at states that the difference in tire size from my original 15" wheels will incur a 10% variance in my speedometer.

How does one go about recalibrating it, or do I just live with the fact that it is not accurate?

graniterover
08-06-2009, 08:54 PM
You could get a different speedo (from a 109), or just do the math. It's less a reflection of the wheel size than the tire size. I have some 15 inchers that are 34 and 16's that are 32. I'm sure someone could recal your existing one, but I'd hate to know the price.

I believe you'll be off by about 5 or 6 %. Not much.

Where in NH are you? I'm in the Nash area.

Mark

K Madigan
08-06-2009, 09:07 PM
you are right, it is the tire size that makes the difference, I stated it wrong.

I live near Warner off of 89.

graniterover
08-06-2009, 09:19 PM
Well, for what it's worth, my truck (with the same tires you have - saw your other post), is off almost nil at 30mph. I have been radar tested by the police radar trailer in my town about 50 times. Even at 45 it's pretty close.

Nice truck!

Mark

oops - my truck is a standard 88, so came with 15's.

Jim-ME
08-07-2009, 04:39 AM
These folks will recalibrate a speedo http://www.nisonger.com/index.htm. But as Mark said the price might scare you. Another option is to buy a GPS and use that to measure speed.
Jim