Speedometer vs GPS
Senior Member
Joined: Jan 2000
Posts: 3,205
Likes: 3
From: Along Lake Erie
OK, so here's the question: Is it off by 6mph at all speeds, or just at 60? How far off is it at 30 mph?
If it's off by 3 at 30, 6 at 60, and 9 at 90, then yes, it's a signal issue, either from the trans to the PCM or the PCM to the cluster. If it's off by 6mph across the board, either the needle slipped on the peg, or the cluster is bad.
-Joe
If it's off by 3 at 30, 6 at 60, and 9 at 90, then yes, it's a signal issue, either from the trans to the PCM or the PCM to the cluster. If it's off by 6mph across the board, either the needle slipped on the peg, or the cluster is bad.
-Joe
Senior Member
Joined: Dec 1969
Posts: 996
Likes: 1
From: TUCSON,AZ,USA
Tire wear can make a difference in the speedo reading also. As the tread goes down the speed will read different.
With my Magellan GPS my speedo is one mile per hour slow. If I see 70 on the speedo I am going 71 according to my GPS>
With my Magellan GPS my speedo is one mile per hour slow. If I see 70 on the speedo I am going 71 according to my GPS>
Certified Goat Breeder
Joined: Feb 1999
Posts: 6,182
Likes: 19
From: the moral high ground
Originally Posted by T Ellenberger
Tire wear can make a difference in the speedo reading also...
Her tires looked great for 25K and had a ton of tread left or so I thought.
I bought a new one and couldn't believe the difference in tread depth between a 'new tire' and a 'good tire' with many miles left in it.