Both of my 525t's have/ had speedo error of 9% fast. (Reads fast- Spedo says 70MPH, real speed is 64). The factory claimed that 9% was acceptable and within factory specs. I say/ said bullsh... Both cars had/ have factory tires & wheels. In Germany, I was told that TUV regulations spelled out an error no greater than 3% across the middle 1/3rd of the gauge. I would think there would be an adjustable rheostat or something to dial it in. Has anyone else noticed this kind of error? Granted, it does help with the tendency to speed. And, what if you had a warranty problem when your odometer read 50,001?