Consider that with an EV and the currently relatively limited charging infrastructure losing 5% in range is a bit much to handle.
If your product improves performance, a P100D currently does 0-100 in around 2.3 seconds, and given this is incredibly close to the theoretical limit, I'm guessing it won't do much there.
The top speed is likely not going to change because the motor speed is more controller limited than air turbulence affected so that one's out. In any case economy would improve if this was improved.
So that only really leaves high speed cornering ability which would be affected above 100kph but would worsen range from around 80kph already.
So the long and the short of it is, give us numbers, don't imply something that's pulled out of a hat please.
My guess is kWh per km at 80, 100, 120 & 150kph would be good to know. The Tesla's trip computer gives that figure already as you drive so on a wind still day on a level road post acceleration phase averaged over A to B then B to A should give some real numbers. As someone else mentioned 30k each should be OK.