Still, Tesla is doing more than just dropping a huge battery into its Model S cars. The company is squeezing every bit of available juice out of its vehicles. While the 85kWh unit hits a 300-mile range (according to EPA measurement methodology), the smaller batteries do well, too. The Model S's 60kWh battery gets 230 miles of range, while the 40kWh version hits 160 miles. In terms of miles per kilowatt-hour, that's better than the Volt or the Leaf. It's also competitive with the Tesla Roadster -- a $109,000 two-seater built in 2008 that weighs 1,900 lb less than the Model S.
"Even though the Model S is a much larger and heavier car than [the] Roadster with ridiculously more cargo capacity, the total battery energy consumption on the highway is only about 10 percent more than the Roadster," wrote Tesla CEO Elon Musk and CTO JB Straubel in a recent blog. In their blog, Musk and Straubel point to a graph showing that the Model S, traveling at a constant speed of 20 mph, can get more than 450 miles on a charge. From 50 mph to 70 mph at constant speed, the vehicle gets between 240 and 335 miles of range.
Amidst the tumult of the recent Model S introduction, Tesla hasn't yet detailed how its engineers are able to do that. When we talked to Straubel in 2009, he identified a multitude of little features that when taken together, give the company more miles per kilowatt-hour than competitors. Straubel cited innovations in cooling, aerodynamics, and rolling resistance. He also described how specialized brake calipers and the changeover from a two-speed to a single-speed gearbox helped boost the Roadster's all-electric range.