Speedometer issue

Anyone have their speedometer off from the factory? I have the stock wheels and tires still, but my speedometer is off as if my wheels and tires are too small (reads faster than actual speed). The weird thing about it is that the computer is correct. I replaced the stock radio using the iDataLink Maestro which has an OBDII connection and the speed there matches what Waze is telling me on my phone.

I took it to the dealer and they refused to look at it claiming that it's "within tolerance" to be off like that.

 

How you do you know it's off?

 

Mine is too. I had someone ride with me with a gps that had a speedo on it. it read about 5 mph over mine.

 

Because the speedo will say 73, my GPS and OBDII reader say 70, and if I pass one of those radar stations they like to pop up every now and then it matches my OBDII reader and GPS.

 

Ahh, so it's a potential ticket saver then.....

 

Not really, I don't go speeding everywhere and I would like to not have to rely on an alternate source to get my true speed.

 

Well now that you know it's off by 4.2857%, it's easy to do the math on the run..........

 

That's a 4% error and within spec.

 

Tolerance on a Ducati motorcycle is 12%. For what its worth anyway. I would drive it and not worry about it.

 

My second gen has the same problem - I hope there's a better answer than "live with it" because it bothers my OCD.

 

You could get a hypertech and dial it in to GPS precision, otherwise you are within spec: https://www.fmcsa.dot.gov/regulations/title49/section/393.82

 

Who rides a Ducati at the speed limit? Nobody I know.

 

3 mph off @ 70.
Don't let anyone tell ya life ain't a bitch..

 

I heard that Honda had a lawsuit about speedos that were too accurate, @Shellshock I heard that from you right?

 

I remember the thread but I don’t think it was me that said it

 

My honda was the only vehicle I've ever had spot on from factory, although the tacoma was pretty close.

Just remember, "officer, I was definitely going the speed limit, according to my speedometer, which may legally be as much as 10% off!"

 

Just put on 3% bigger tires. Problem solved!

 

All speedometers are off at some point, always have been. We just didn't know it until we got GPS's. When you have a set of tires that are near the end of their life they are enough smaller in diameter to cause 5% or more difference compared to when they were new. Even if it is right on the money when new, it will be off again after your tires wear down. Messes with the odometer too.

 

With my 33s my speedometer reads 70 when I'm really going 73.

Get bigger tires and you'll be set.