Here's a few. It's from a European rule that states that the speedo can never read low even if the owner replaces the wheels and tires with the largest reasonable alternative.that's a weird design, what was their reason behind it? I can't seem to find this coverage you mention on google
I've had the same question for almost 3 years now. We all know it's 7% off...ok great... nice to know. Now how can it be fixed? If you hook up to ODB II port you can see how fast you're going with it? If that's the case (and I think it is), then you would think its a lest possible to tweak the ECU and fix that problem. This issue is frankly the most annoying problem I've had because I've seen no fix. I have an ECU guru that is working on a custom tune for me right now because a supercharger and a custom ported/polished head has been put on the car and only thing possible is a one-off custom ECU tune. I'll ask him about this...maybe he can provide us with a fix.One of the posts said it's built into the ECU(?) or maybe the gauge cluster? Maybe it can be reflashed to remove the ~7%?