During yesterday’s Q1 2020 earnings call, Tesla CEO Elon Musk revealed the flagship Model S should actually have a range that is 9 miles higher than the current rating, topping out at an equal 400 miles (643km).
The reason it doesn’t have an official 400 miles range (yet) according to Musk was due to the EPA leaving the test vehicle overnight with the door open and key inside. This left the car in a “waiting for driver” state, resulting in a 2% drop in battery capacity.
Musk added that once the EPA reopens after coronavirus lockdown orders are lifted, they will conduct new tests that will give it the coveted 400 mile range estimate. If true, that would make Tesla the first automaker with an EV capable of travelling such a long distance on a single charge.
Earlier this year, Tesla updated the Long Range Model S to the Long Range Plus, boosting the range to the current 391 miles (629km). The Model X was also renamed the Long Range Plus, and received a similar range update to 565km (351 miles).
Keep in mind these increases in range are a result of efficiencies gained through software update, and no physical changes to the battery packs have occurred.