The changes mean that, while you can still get a bare bones, rear-drive Model S 70 for $70,000 (plus $1,200 in destination and documentation fees), the ticket for top battery bragging rights now starts at $88,000 for the 90D. The company has, in the past, discontinued some battery sizes, saying the take rate had been too small to maintain. While it hasn't explicitly said that was the reason this time around, a statement to Autoblog from a spokesperson makes it seem likely:
The recently introduced 90kWh battery pack offers unprecedented range and value that has been well received by our customers. As a result, we will no longer be offering the 85kWh battery. Model S is designed to be completely customizable, ensuring that customers are able to build the car that meets their unique needs and Tesla is committed to continued innovation and the development of industry-leading technology.
The 90-kWh battery was introduced last summer, at the same time as Ludicrous mode and the 70-kWh version, and with dual motors returns a stated 288 miles per charge. The Model X, which Tesla launched last September, never had the 85-kWh option, with buyers always having to choose between the 70- or 90-kWh pack.