Ever since Tesla revealed that the refreshed Model S 70D was actually a software-limited 75D, the speculation has been rampant that the 90kWh battery pack in the 90D and P90D models was actually a 100kWh battery that was similarly software-limited.
Of course, Tesla's not commenting on whether or not the 90D is actually a 100D in disguise, but we really, really doubt it. It could be, but it's not. So stop it.
What keeps fueling this speculation is that people looking at new and used Model S options in the Tesla inventory stock and seeing both 70kWh and 90kWh vehicles with varying notes about range upgrades. Some say nothing about a range option, some read "Range Upgrade", while others read "No Range Upgrade."
The startling inconsistency should be a red flag that these listings are assembled by humans and not automated like the big car manufacturers and really shouldn't be read to deeply into. The fact that it's inconsistent with the pre-refresh 70 and 70D whether or not there's a "No Range Upgrade" or "Range Upgrade" — when there were no 75kWh packs in the Model S line-up, even secret ones — should be enough to squash the speculation right there, but apparently it's not. And as Tesla Motors Club member wdolson notes on his just-delivered Model S 90D, his configuration sheet says "Range Upgrade - Included". Heck, the "Range Upgrade"-labeled Model S could be from the months-long period where Tesla sold both the 85D and 90D, with the latter as an "upgrade" over the previous top-capacity pack.
There absolutely is inconsistency in how Tesla is describing the range upgrade possibilities for their new and used inventory Model S stock, but that doesn't mean Tesla's hiding something about the 90kWh battery packs.
It's also worth considering that when Tesla rolled out the refreshed Model S, it leaked almost immediately that the 70 and 70D were actually software-limited 75kWh cars, in keeping with the 75kWh pack available for the Model X SUV. Within three weeks Tesla made the optional upgrade public, offering an additional 15 miles of range for $3,000. The 90kWh pack was introduced in July, 2015 — nearly 11 months ago — and there's been zero indication that it's been altered or updated in any significant way since then. It's an option for both the Model S and the Model X.
Is there a 100kWh battery pack coming? Without a doubt. But it's not been hiding under our noses this entire time.