Last year Elon Musk promised an upgrade to the battery of the Tesla Roadster, and in December the first details of the “Roadster 3.0” came out. On the one-year anniversary of the first Tesla cross-country rally last year, an upgraded Tesla Roadster drove for 340 miles on a single charge from San Jose to the Santa Monica pier, without plugging in once.

Thanks to battery cell enhancements, aerodynamic improvements, and low rolling resistance tires, Tesla has been able to improve driving range by about 40 to 50% on the Roadster over the official 245 mile EPA-rated range. According to the official Tesla blog (which just got a much-needed upgrade), the team of two drivers completed the six hour journey from San Jose to the Santa Monica pier covering a total of 340 miles at “around the speed limit” and still managed to pull in with 20 miles remaining on the battery pack.

While not quite the 400 miles Elon Musk had initially asserted, it’s a sizable improvement, giving the Roadster a lot more viability in daly driving, and about 100 miles more of driving range than the 85 kWh Model S. Alas, Model S owners hoping for a bump in range had better not get their hopes up, as the Roadster upgrade takes improvements from the Model S and retroactively improves the original Tesla vehicle. As the disclaimer at the top of the blog post reminds us, there are no expected range increases for the Model S anytime soon.

However, given that Tesla has a habit of upgrading their vehicles, and that the battery packs are easily swappable, a 500-mile Model S isn’t out of the question. One day.