Tesla Motors is about to ramp up production of its Roadster, having secured supply of a new single-speed gearbox from BorgWarner. Tesla began producing the Roadster in March 2008, but all 27 cars so far delivered to customers have effectively been interim models because the original two-speed box was deemed too fragile for long-term use.

So what’s the deal with Tesla’s latest Roadster?

The original thinking was that the Roadster would require two gears to achieve the best possible acceleration, and on that point Tesla was right. The two-speed ‘box used in the first cars made for a staggering 0-60mph time of just 3.9 seconds, but it came at the price of having to replace the transmission every few thousand miles.

Consequently Tesla set about developing a single-speed transmission, and all the existing cars will now be retro-fitted with the new 'box. Production of the single-speed cars will now start at ten Roadster per week, increasing to 40 per week by early 2009.
Tesla has designed the new ‘box to yield higher peak torque levels, so the production cars will develop 280 ft lb, a 69lb ft increase on the first model. In addition the Roadster now has a longer range, travelling 244 miles on a single charge compared to the original cars' 221.