Thanks for the input,, BB,, that old suit against Honda goes back to the '80s and was even true on their original Civic's. Makes one wonder why they would continue to produce speedo's which read low for another couple of decades. I have checked both my odometer and my mileage computer,, using pump volumes and gps distances. Both read low by just under 4%. About 1% of that error is attributable to my rear tire size. Funny,, that my '80s vintage bikes also exhibit a 3% speedo and odometer error,, and of course those are mechanical. Maybe the best approach to error correction is to adjust one of the readings to actual,,, and not worry about the the other two. I would not mind my speedo being precise. Distance and fuel consumption I usually check manually, as mentioned above. But since I am always flirting with speed limits +,, and don't always mount my gps,,, that would likely be the best choice for me,, Cat'