I have a Model S 75D that's been "unlocked". The other day I was cruising at 80 MPH and I stepped down on the accelerator and I noticed that the car accelerated from that point very slowly. My battery was at least 3/4 full and the air temperature was about 65 F. Acceleration at lower speeds is very quick so I was surprised when this time it was very slow. Given that my top speed is reportedly about 130 MPH (not that I would go there), is what I experienced normal?