Tesla Motors announced today that it has prototyped a "Roadster 3.0" package, which Roadster owners will be able to purchase in the future to update the battery pack, aerodynamics, and tires of their 2008-2012 Tesla Roadster electric sports cars.
Taken together, the updates are expected to boost the Roadster's rated range 40 to 50 percent, from 244 265 miles to something near 400 miles, according to various comments by Tesla CEO Elon Musk.
In a blog post, Tesla said, "There is a set of speeds and driving conditions where we can confidently drive the Roadster 3.0 over 400 miles."
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"Battery technology has continued a steady improvement in recent years, as has our experience in optimizing total vehicle efficiency," the company said.
"We have long been excited to apply our learning back to our first vehicle."
The first of the three elements of the retrofit will boost battery pack capacity from the old 53 kilowatt-hours to "roughly 70 kWh" in the same form factor.
Tesla Roadster final assembly, Menlo Park, California, April 2009
This is accomplished by using "a new cell that has 31 percent more energy" density than the original Roadster cell.
The second consists of an add-on kit to improve the car's basic aerodynamic profile, developed using "modern computational methods." It will cut the car's aerodynamic drag--especially at high speeds--that chews through battery energy.
Tesla said it expected the aero kit to cut the car's drag coefficient by about 15 percent, to 0.31. For purposes of comparison, the most aerodynamic vehicles over the last several years have drag coefficients in the 0.24 to 0.26 range.
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Finally, the third component will be tires with lower rolling resistance. Tesla stated that the coefficient of rolling resistance of the new tires will be 8.9 kilograms per ton, down from 11.0 kg/ton for the Roadster's original equipment tires.
Last July, during an interview with British car magazine Auto Express, Musk promised a "new-generation battery pack" for the Tesla Roadster with "a range of about 400 miles."
As is often the case at Tesla Motors, this week's news had been previewed in three tweets by Tesla Motors CEO Elon Musk.
Elon Musk signs new 2013 Tesla Model S at Tesla Store opening, Austin, Texas [photo: John Griswell]
The first came on Monday, simply saying that details of the Roadster battery upgrade would be released this week, and noting that several "higher-priority crisis issues" had pushed the announcement date out further than planned.
Then came two tweets on Christmas Day, December 25. The first promised details the following day, and reiterated that the new pack "will enable non-stop travel from LA to SF -- almost 400 mile range."
Musk followed up with a second tweet: "Should mention that a battery pack upgrade is not coming soon for the Model S, but it obviously *will* happen long-term.")
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Tesla said that it will conduct a real-world demonstration of the increased range "in the early weeks of 2015," by driving a Roadster 3.0 non-stop from San Francisco to Los Angeles.
No details on price, timing, or availability were provided in today's announcement.
But, offering a vision of regular updates to range and performance, Tesla said, "We are confident that this will not be the last update the Roadster will receive in the many years to come."
That's a statement foreign to the established world of global automakers, who modify cars they have sold only in response to government-mandated recalls or occasional customer satisfaction issues.