Speedometer Off

I have a 03 300A @ 60k, I bought the MM used a little over a year ago @ 34k. When I bought it I noticed my speed was off by 10mph, if the speedometer read 80mph then I'm only going 70mph. My tire size is still at factory standards, the only thing I could come up with is that I could possibly have 4:10s already installed from previous owner and they just didn't get it tunned for the 4:10s! I plan to check the driveshaft this weekend for the 4:10s but if it's not that, any suggestions or has anyone else out there had this problem?? Thanks
:beatnik:

If it is off by 10 MPH I would say the axle ratio is off in the tuning, the car may have a tune in it, or it may have been returned to stock before the previous owner sold it and it does have 4:10 in it.
 
I have a 03 300A @ 60k, I bought the MM used a little over a year ago @ 34k. When I bought it I noticed my speed was off by 10mph, if the speedometer read 80mph then I'm only going 70mph. My tire size is still at factory standards, the only thing I could come up with is that I could possibly have 4:10s already installed from previous owner and they just didn't get it tunned for the 4:10s! I plan to check the driveshaft this weekend for the 4:10s but if it's not that, any suggestions or has anyone else out there had this problem?? Thanks
:beatnik:

Omg that car is a BABY!!! My girl is at 155K
 
If you have sct programmer plug it in and go into program and to gear ratio and choose 4.10 and test it, if its still not good try 3.73 if no good also try all the options until it's corrected, if is there no good in that it should be something other than programing.

Sent from my ASUS_I001DC using Tapatalk
 
If you have sct programmer plug it in and go into program and to gear ratio and choose 4.10 and test it, if its still not good try 3.73 if no good also try all the options until it's corrected, if is there no good in that it should be something other than programing.

Sent from my ASUS_I001DC using Tapatalk

You’re right around 12 years and 2 days late for the party. [emoji6]


Sent from my iPhone using Tapatalk Pro
 
just going to throw this out there . when you bought the vehicle did you run a car fox on the mileage . ? point being the needle has to come off to roll back the numbers . not saying that is the problem , but ????????????? . hope thats not the issue. i recieved a huge refund on a rolled back speedo when it was proved to be true .
 
Last edited:
Back
Top