The final cut of the 9th episode of the Tesla Motors Club Podcast, featuring Chad Schwitters, the former president of Plug In America, is now available. You can watch it now on YouTube or listen to it on all major podcast networks.
"According to the EPA, there is no range advantage for the 90kWh option. However, as we’ve seen before with the Chevrolet Volt., it’s likely that Tesla didn’t submit the 90D or P90D for EPA testing, thus it’s stuck with same exact official figures as the 85 kWh version.
But Tesla does state time and again that the 90 kWh battery gets you approximately 6% more range, so figure a combined range of 286 miles for the 90D and 268 miles for the P90D."
The 90D pack I believe is almost exactly the same weight as the 85. The increased capacity is due to a larger concentration of graphite in the anode. If you add 5kWh to the pack, you HAVE to have that additional capacity available as more range. The only explanation is that the 90D hasn't been tested. Otherwise, the cars are virtually identical.