Earlier this month, Tesla (TSLA -1.46%) said its P100D Model S was about to get a performance boost through an over-the-air software update. Already the world's fastest-accelerating car currently in production, it's difficult to imagine the car's 2.5-second zero-to-60 time getting any better. But, according to a tweet from Tesla CEO Elon Musk on Wednesday, a faster zero-to-60 time is indeed on the way.

Model S. Image source: The Motley Fool.

"Looks like the Model S P100D Easter egg will allow it to do 0 to 60 mph in 2.4 sec and a 10.6 sec 1/4 mile via software update next month," Musk said. 

The company's Model X SUV's zero-to-60 and quarter-mile times will also improve by 0.1 seconds, Musk said in another tweet.

As an "Easter egg," owners will have to search for a way to unlock the performance boost. Tesla has hidden Easter eggs in its software before, including a Mario Kart-like rainbow road that displays in the dash, a warp-speed-looking 5-second animation on the 17-inch touch screen, among others. This Easter egg, though, is the first to unlock a significant performance enhancement.

Does it matter?

There are several reasons Tesla software updates like these are notable. First, by delivering a significant performance update for its flagship versions of Model S and Model X, Tesla continues to demonstrate the value its software can bring to its fleet over time. Second, software updates likely also help boost press coverage and word-of-mouth marketing, both of which are particularly important to Tesla since it doesn't pay for advertising.

However, it could also be said that investors already expect Tesla to deliver this kind of value to customers, making moves like this more of a requirement at this point rather than a bonus.