The Model S. Image source: Tesla Motors.

"Tesla product announcement at noon California time today," Tesla (TSLA 12.06%) CEO Elon Musk said on Twitter Tuesday morning. While it's unclear what the electric-car maker will announce, there are a few things the company has hinted it has in the works, including an update for its driver-assist Autopilot technology and possible P100D versions of its Model S and Model X.

Here's why an Autopilot update or a P100D could be one of the announcements made today:

In July, Musk said on Twitter he thinks "significant improvements" for Autopilot may be possible via an over-the-air software update.

And rumors of Tesla's P100D ("P," 100, and "D" stand for performance, 100 kilowatt-hour battery capacity, and dual-motor all-wheel drive, respectively) gained momentum last week when it was revealed Tesla received official approval to manufacture 100D versions of the Model S and Model X in Europe.

Also supporting the possibility of a P100D, Musk complimented a hacker earlier this year who discovered a cryptographic message in Tesla's 7.1 firmware translating to a "P100D" designation.

Other announcements are possible, of course, but these seem the most likely.

Does it matter?

With Tesla planning to ramp up deliveries to 50,000 vehicles in the second half of 2016 -- up from about 29,000 in the first half of the year -- a product announcement related to its Model S or Model X would definitely be well-timed, especially since Model S sales have been declining sequentially for two quarters.

Stay tuned at The Motley Fool today for an update on the product announcement.