Originally Posted by wpoll

I took note of the speedo vs BC menu #8 V: value today...



I should have verified these values via a GPS at the same time, as these values are with a set of tyres at pretty much minimum tread depth. I want to perform the same check once I replace the tyres so I can gauge the variation over the life of the tyres. This will affect any correction factor I might code, as no one correction factor will read TRUE speed for the entire life of a set of tyres. I'd like to set a correction factor that doesn't ever result in a speedo reading UNDER the true speed...