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      07-18-2012, 01:35 AM   #16
Platinstorm
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Drives: E46 318i 1998 / E92 330i 2006
Join Date: Jan 2012
Location: Germany, BW

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Quote:
Originally Posted by Ammonia View Post
I believe something to do with electric motors themselves doesn't require them to have as many, but they usually do. The Tesla Roadster, for example, has two gears.
I thought it was one of the benefits of electric cars do not need to shift?
They changed the gearbox to an single-speed gearbox

on wiki you can find:

Quote:
The company previously worked with several companies, including XTrac and Magna International, to find the right automatic transmission, but a two-gear solution proved to be too challenging. This led to substantial delays in production. At the "Town Hall Meeting" with owners in December 2007, Tesla announced plans to ship the initial 2008 Roadsters with their interim Magna two-speed direct shift manual transmissions locked into second gear, limiting the performance of the car to less than what was originally stated (0 to 60 mph (0 to 97 km/h) in 5.7 seconds instead of the announced 4.0 seconds). Tesla also announced it would upgrade those transmissions under warranty when the final transmission became available.[50][52][91] At the "Town Hall Meeting" with owners on January 30, 2008, Tesla Motors described the planned transmission upgrade as a single-speed gearbox with a drive ratio of 8.27:1 combined with improved electronics and motor cooling that retain the acceleration from 0 to 60 mph (0 to 97 km/h) in under 4 seconds and an improved motor limit of 14,000 rpm to retain the 125 mph (201 km/h) top speed.[92] The upgraded system also improved the maximum torque from 200 to 280 ftlbf (270 to 380 Nm) and improves the Roadster's quarter mile times.
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