My record of 199 miles for a single charge has no external charging, as I have used 14.1 kWH shown in the DIC. But it was from the highest elevation that I can find, drove like a grandma in the windflow level road, then when battery was depleted, drove downhill at optimal speed for regen, and when the battery nears full from the regen drive level road again and repeat the process. The overall conversion efficiency of potential energy from elevation change to regen is approximately 75% and by driving carefully I didn't lose anything to friction braking. My record can be beaten if a higher elevation can be found to start driving.
The 75% recapture from regen seems to agree with GM statements in the past.
Going 199 miles on a single charge can be misleading without knowing it's really 199 miles with lots of coasting/regen down a mountain road. A bit like loading the fully charged car into a rocket, shooting it around the moon, bringing it back to earth, and claiming the car traveled thousands of miles on a single battery charge. It did technically, and it didn't in the way most people would travel on a charge.
In both cases, the energy it took to get to those heights and make the claims is not accounted for. The regen/recapture traveling downhill is recovering what? The energy it took to go UP the mountain. No free lunch.
Same with orbiting the moon. It took a lot of energy to boost the car into orbit. So both claims, to be accurate, should account for the energy used to go uphill in order to go downhill. I suspect a net energy loss in both scenarios. The 75% regen recapture suggests that at least 25% of the energy it took to go up the hill was lost going down.
If gas was used to go up the hill, it's even worse. Gas engines are only 25% efficient at best, wasting 75% as heat and noise. But maybe I am all wrong. How did you get up the hill to do your downhill, record setting "199 miles on a single charge"?