Tesla announced a goal of 300 miles for the range of its Model S electric sedan early in its development. As the company came closer to production, it said that only the top-trim Model S, with an 85-kilowatt-hour battery pack, would achieve the 300-mile figure. Less expensive versions of the car, with 60- and 40-kilowatt-hour batteries, would hit 230 miles and 160 miles, respectively.
Today, in a somewhat technical and involved blog post from Tesla founder Elon Musk and CTO JB Straubel, the company revealed that the 85-kilowatt-hour Model S only achieved a range of 265 miles.
The post initially points out that computer models, using parameters such as constant speed, flat ground, no AC or heat, and 300 pounds of people and/or cargo, showed the Model S achieving just over 300 miles at 55 mph. At 30 mph, that range goes up to 425 miles. If nothing else, those figures demonstrate the effect of higher speeds on electric range.
Further, Tesla's post points out that the Model S hits 320 miles from a full battery under the EPA's former two-cycle test. The two-cycle test covers city and highway driving, with a maximum speed of 60 mph.
However, the EPA added three cycles to its testing procedure for determining estimated fuel economy of 2008 and later-model cars. These new cycles include running with air conditioning, heating, and at speeds up to 80 mph. The more demanding five-cycle test produced the lower figure for the 85-kilowatt-hour Model S. Tesla has not said what ranges the 60 and 40 kilowatt-hour versions of the car achieved as of yet.
By comparison, the Nissan Leaf only drives 73 miles under the five-cycle test. Nissan often cites the Leaf's LA-4-cycle range, a test at low speeds simulating city traffic, of 100 miles for range.
Even with the lower-than-expected EPA test range, the Model S should rank as the highest-range production electric car. The 85-kilowatt-hour Model S goes on sale this summer, followed by the 60- and 40-kilowatt-hour versions later in the year.