Speedometer and Odometer read incorrectly

[K-Dawg]

I haven't done any serious testing, but my speedometer and odometer/tripmeter read incorrectly. Its not a real big deal to me, just annoying. I have stock sized tires.

When the speedometer shows an indicated 80mph, I think I'm really doing about 85mph. When I'm running flat out, I think it shows mid 130s.

On a trip I took yesterday, a sign said it was 97 miles to my destination, but my tripmeter was about 4 miles shy of that when I got there. My gas mileage has also been consistantly bad since I've had the car.

Why would this happen? Speedo cable sticking? Is my instrument panel going out?

 

[NotSoSlowSHO]

speedo gauges dont just "go out".

They either work, or they dont. Sometimes they stick, but that just results in a bouncy needle.

Assuming the speedo hasnt been tampered with, the ONLY variable is your tire diameter.

 

[Ishodu]

SHO speedos usually read low. You can calibrate them. There is an article on shotimes that SHONUT made on how to do this, I have done it with great success.

 

[K-Dawg]

The needle doesn't bounce.

I'll check out the article on SHOTimes.