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Speedometer accuracy

2K views 9 replies 7 participants last post by  mrk4543 
#1 ·
Has anyone had their speedometer checked for accuracy? Mine seems to be reading high when going by the highway radar displays...such as an indicated 70 shows as 63 on the radar display. I did have the diff replaced not too long ago and wondering if there was a ratio change. Going to check elapsed time on interstate with mileage markers in the next few days.

Marty
 
#7 ·
^^^^
A good idea. Around here, there is a road that has a measured mile that would serve that purpose. (For Cleveland locals, it's Rockside Rd. in Garfield Heights/Valley View if the AAA signs are still up. Will have to look this weekend.)

Couldn't it also be that the radar sign is busted and is throwing out the wrong speed?
 
#8 ·
It is quite possible the radar display was broken....wouldn't surprise me at all since it belongs to the Highway Department of the State of Disrepair (Florida)....that is why I am going to check it on measured mile. The interstate mileage markers should be good enough for this type of check....of course, they are administered by the Feds...what could possibly be incorrect?

Marty
 
#10 ·
It would appear that the mileage paddle markers on the interstate are no where near being properly placed.....checked out the paper work on the diff replacement with the car's build sheet and the part numbers etc. seem to be proper. Not too much else to do until I can get to a measured mile or get to a shop to have the speedometer calibration checked. Life goes on....

Marty
 
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