To improve safety and durability, design changes were made during the building of the first validation prototypes of the Tesla Roadster. As a result, the company has downgraded the electric vehicle’s range from 250 miles to “greater than 200.”
Changes made to increase the car’s safety and durability increased the weight by several hundred pounds. In addition, the company selected li-ion cells with a slightly lower capacity than the largest cells available because the smaller and more mature cells have better long-term durability and higher abuse tolerance.
Writing on his company’s blog, CEO Martin Eberhard said that the company sent letters out to the company’s customers last week informing them of the decisions. As he describes in his post, it was not one or two large additions but a long list of small items, all of which added up to the additional mass.
Maybe I was a bit naive expecting to hold the line on mass. Those of us at Tesla Motors who have a long automotive experience say that fixes to problems discovered [at] this stage of the program always adds mass.
The upside of all this is that the Tesla Roadster will be a much more reliable car for having added this mass.
At more than 200 miles, the Tesla Roadster will still have the highest range of any production EV in history by a large margin, and we will continue working hard to deliver even better range in the coming months.
Eberhard said that the company is holding to a floor of a 200-mile range, and striving for upward revisions. The target for acceleration remains the same, because improvements in the drivetrain have offset the additional weight.