Compared to our S P85, the rated range on our S 100D appears to be closer to typical highway speeds.
On our road trip this weekend - started at 90% (307 miles) each way - 175 each trip. On the way out, we ended up with 90 miles of range left at the destination. On the return home, we had 115 miles left. And the Trip Planner was fairly close to predicting the charge level at destination.
With our S P85, the Trip Planner was always much too optimistic - and we'd often see the battery charge prediction at destination quickly drop after leaving a supercharger, forcing us to slow down.
Could be a combination or more range with the 100D, more efficient use of the dual motors, or the battery usage calculations for the original P85's were off.
With our P85 - we had to stop 5-10 minutes each way at a supercharger, and still often ended up with only 20-30 miles of range left. With S 100D, not only don't we have to stop at the supercharger - we have around 100 miles left after driving 175 (and that's without charging to 100%).
I realize we may see some degradation - like the 5% we saw with our P85 - but even with that, the S 100D would be performing better than expected...