My brother and I go around with this subject every so often. He says speedos are off by 8% to keep people slower. Same in cars starting in the eighties. I go a hun. and he says it's only 92. Some of the speed readers I go by will say 2-3 miles slower than my gauge. So the speedo reads slow and the odometer shows correct? How stupid. Don't ya want a accurate gauge? Is the error the same throughout the gauge range... Makes me want to get into the gauge and move the needle! HA ha. I know, don't even try.