I always thought 0-60 times were measured with half tank of fuel and driver&passenger.
If its only driver, then reduce the fuel load to compensate for some of the weight of the passenger.
There is no way that a driver alone will get a decent reading unless the car is geared up with the correct tools.
Forgot this was a serious scientific forum! 

Yeah you're right about uncalibrated speedos - but maybe I was going down hill, with the wind behind me and I was slipstreaming a bus.
See
Keep the laughs coming Tin 

btw - electronic speedo's are not all calibrated accurately  
