While some manufacturers are being investigated by the EPA for declaring false efficiency numbers, the Tesla Model S seems to be exceeding them. A Model S owner from Florida decided to try and see just how far he could travel with the juice stored in the car’s 85 kWh battery pack.

The owner, David Metcalf took his son Adam on a 423.5-mile or 681 km drive aboard the top-spec electric sedan, before it finally ran out of juice and had to be towed back home. This may seem far-fetched, but Elon Musk has said before that he thinks the car is capable of breaking the 400-mile barrier, and while this information may be unofficial, the Tesla CEO has already posted on his Twitter account, congratulating David on his achievement.

Now, the EPA has just rated the Model S, fitted with the lower capacity 60 kWh battery pack, at 208 miles autonomy, yet it is also a few MPGe more efficient, so breaking the 300-mile barrier should not be a problem, with the necessary preparation, and suitable roads – the tires also need to be pumped up more, to reduce rolling resistance, but that`s pretty much the only thing the owner can do before attempting a run like this.

By Andrei Nedelea