I found my speedometer was off by 7.2 percent (give or take a tenth) when I bought my SpeedoHealer and 15T sprocket ON TOP OF the 6.9 percent the 15-tooth brought on, which means my gas milage was NOT originally 46mpg after all. More like 42.5mpg!!! I'm figuring this is still good though.

Having worked at GPS from 1993-1997 I realize during "war time" selective availability is turned on which means civilian accuracy is intentionally off by about as much as 5% but under sustained conditions it should be closer to 1 or 2%. This is for the baddies to miss targets enough such that bombs don't dead-on targets but military ones do. Enough of an innaccuracy to be a deciding factor without pissing-off the pubilic (even though it IS a courtesy by the AirForce for FREE).

Er.. anyway, I remember reading a few years ago in Cycle World or some such rag that many bikes can be off by up to 10.9% on the speedo, and all of them are set high, not low, due to DOT standards. I suspect companies do this on purpose. Kawasaki was notoriously high with their ZX-10, interestingly, as was Yamaha's R1. Each company seems to set different bikes to different percentage errors, so it's not all the same throughout the company, ie. all Hondas are not 7.2% high, etc., but all Superhawks might be 7.2% high.

With this in mind, I'm wondering and doubting that people getting 37mpg or less are actually getting more like 34mpg due to non-speed-corrected speedometers.

For those that actually went and calibrated, how off was your SHawk?

I found my digital fuel guage blinks red with 3.1 gallons used at 124 miles pretty consistantly now with a few +100mph runs during the cycle with my 15T installed and a 14.1% correction, meaning I'm getting about 40mpg. I could probably squeeze out another 1 or 2 mpg. I expected a small loss due to the constant 5k running speed at 80mph anyway.

Okay, I'm done ranting now!