[ltlfeat]

Lots of MPG posts but there not worth much if our odometers aren't
accurate. My speedometer is off 10%, any info on the odometer

 

[Lonewuff]

The odo is accurate, it is just the speedo that is off. I ran the speedo and Odo against the GPS and discovered the speedo was off by 10% and the Odo was very close to the GPS.

 

[dshealey]

Lots of MPG posts but there not worth much if our odometers aren't
accurate. My speedometer is off 10%, any info on the odometer

Yes, hundreds of posts over the years regarding speedo/odo accuracy, and many, many posts regarding the fix for the speedo error on pre-'05 models.

If you search for speedo accuracy, you will find way more than you can, or will want to read in a week.

The speedos on the '99-'04 LTs is about 10% fast, the ODO about 2-3% so. The Speedo can be relatively easily fixed to read just about perfect, not so the ODO, which cannot be calibrated.