Tesla has settled on a BorgWarner single-speed gearbox its Roadster and is finally initiating a ramped-up production rate. Roadster engineers developed specifications for the new gearbox and provided them to BorgWarner – the huge US based transmission manufacturer. One-speed fits allThe new gearbox is an integral part of an enhanced powertrain with significant performance and efficiency improvements. The new powertrain delivers about 30% higher motor torque on a single gear ratio, and it achieves a 10% higher EPA combined range.“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.”More performance, better rangeThe new gearbox is designed for the higher peak torque levels of the new Roadster powertrain, which has increased from 286Nm to 380Nm. The new powertrain achieves an EPA combined range of 393km on a single charge, up from Tesla’s previously announced EPA range of 355km.Production of Tesla Roadsters began in March, and the first vehicles were built with an interim transmission design, which left initial customers a bit miffed, especially after a litany of production delays. 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 to ramp up to at least 20 vehicles per week within a few months and 40 per week by early 2009. With huge global interest in the Lotus Elise based Roadster, demand, especially in Europe, is sure to outstrip supply and Tesla needs to find a way to expand production capacity – fast. “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.”So far, 27 customers have taken delivery of Roadsters.