Tesla has recently built the first couple of validation prototypes of the Tesla Roadster. They were built from hard-tooled components for all body panels, include production headlights, taillights, and interior components (including much more comfortable seats), and many other minor parts. CEO Martin Eberhard is shown with one of the prototypes.
Several design decisions that improve the safety and durability of the car were made, understanding that there would be tradeoffs. The two most significant decisions were:
- Many design changes were made to make it more durable and safe. Most changes added weight, increasing the car’s weight by several hundred pounds.
- Lithium ion cells with a slightly lower capacity than the largest cells available were chosen, because the smaller (and more mature) cells have better long-term durability and higher tolerance for abuse.
Driving range tests were performed with a Roadster that incorporated these design changes (and many others) on an EPA-compliant dynamometer. Based on the results of these tests, it is anticipated that the range of the Tesla Roadster will still be greater than 200 miles, but will not meet the original target of 250 miles.
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 they are continuing to work hard to deliver even better range in the coming months before the first models are delivered. This range is still high enough that most users will not have to worry about charging during a typical day.
They are holding the line on 4-second 0-60 mph acceleration, largely because the extra mass has been offset by improvements in the drivetrain.
Their blog has answers to some of the questions customers asked after being notified about the weight change and reduced mileage.
They are now accepting reservations for 2008 model year cars on a first-come, first-serve basis, the 2007 run having been sold out.