I upgraded my firmware this evening successfully and also installed my 13 volt lithium battery and took the Bug for another ride. This time I had no controller shut down because of low Aux battery. I took my iPhone along because I did not trust the speedo in the car to give an accurate speed reading. I was correct. I got an official 47 mph in 4th at 72 volts. The car has fat soggy tires and a bone stock transaxle. Second was just impossible to start in because the car would just jump and jerk because of so much torque in second gear. I put it in 3rd and it just took right off. But being limited to only 72 volts I hit the peak speed real fast and then dumped into 4th. It runs well and pretty smoothly if I do say so myself. I measured the commutator temp after my run and had a temp reading of 150 F. Pretty good knowing the outside temps were still hanging around 104 F. I did a bunch of hard runs too. Not fast but hard.