"Last December, when the two-speed transmission designed by a previous supplier proved not to be durable, we announced we would modify our approach," said JB Straubel, Chief Technology Officer of Tesla Motors. "By using a more powerful inverter and an enhanced motor design, we were able to implement a single-speed gearbox and still achieve our original performance goals. In fact, the new setup is superior in almost every way."
The new gearbox is designed for the higher peak torque levels of the new Roadster powertrain, which has increased from 286 Newton-meters (211 foot-pounds) to 380 Newton-meters (280 foot-pounds). The new powertrain achieves an EPA combined range of 244 miles on a single charge, up from Tesla's previously announced EPA range of 221 miles.
Production of Tesla Roadsters began in March, and the first vehicles were built with an interim transmission design. Customers who own Roadsters with the interim transmission can have their powertrain upgraded free of charge.
Tesla Motors starts production of 10 new Roadsters each week. Customers typically take delivery four to six weeks after production begins. The company expects production starts to ramp up to at least 20 vehicles per week within a few months and 40 per week by early 2009.
"Successfully implementing the new gearbox in less than a year was an incredible technical challenge and huge accomplishment for Tesla's engineers," said Ze'ev Drori, Chief Executive Officer of Tesla Motors. "Now that we have a final powertrain design, in a matter of months there will be hundreds of Tesla Roadsters across the country. We're heralding nothing less than a new era of the automobile."
(Source: Tesla Motors)