Tesla has now started offering Tesla Model S and Model X cars with 390 miles (approximately 630 km) range. Until now, the top end variant of Model S offered a range of 373 miles.

Elon Musk confirmed on Twitter that all Model S and Model X cars made in recent months already have the improved 390 miles EPA range. Tesla will soon unlock the range for free via software update for the already sold cars.

Elon Musk also revealed that that Model S and Model X may give 400 miles range with the improved wheels/tires. Tesla will also make the new wheels/tires available for all older models.

Instead of announcing a new model, Tesla has been introducing numerous small hardware and software improvements for Model S and Model X over the past few months. So, when you buy a brand-new Tesla Model S today, it will have several improvements when compared to the models from last year or so.