While the first production Tesla Roadsters still will come with a slower-acceleration transmission, Tesla Motors said it has designed a new transmission system that will bring back the original acceleration promise of "0 to 60 in about four seconds" in Roadsters produced later this year.
Instead of the more complex two-speed design, Tesla engineers have come up with a simpler one-speed transmission, which will be engineered to handle the higher powertrain torque, according to the company (see Earth2Tech post and press release).
The electric-sports-car startup said the new transmission will be paired with a higher-voltage power electronics module, which will deliver more electrical currents into the system. (Aside from controlling voltage levels, the module also controls the motor's revolutions per minute, torque and the regenerative braking system, as well as converting direct current into usable alternating current, according to HowStuffWorks).
The motor also will be modified with advanced cooling capabilities to handle the additional power, the company said.
"The planned solution reduces program risk, provides better efficiency, lower weight, equal or better range, better thermal performance and quicker quarter-mile acceleration due to the elimination of the need to shift gears," according to the press release.
Another advantage? The cost of the one-speed transmission should be lower than the two-speed transmission, in the long run, because it is much simpler, according to Darryl Siry, vice president of sales and marketing.
The one-gear system -- which essentially makes the car an automatic -- might seem less sporty than the two-gear manual system, but drivers of the Roadsters with these new systems will get the acceleration they were promised. And the interim transmission system also is a one-speed, according to Earth2Tech.
Transmission problems have already caused several delays to the much-anticipated Tesla Roadster production.
Tesla said it was still on track to deliver its cars on time in December, but later that month announced that the initial Roadsters slated to hit the roads this year would get an interim transmission that goes 0 to 60 in 5.7 seconds, instead of "about 4" as previously promised.
CEO Ze'ev Drori also blogged that the cars would be retrofitted with the final transmission once it is ready, at Tesla's expense. The company reiterated that promise in the announcement Thursday, saying it would provide the upgrades free of change "later this year."
In December, Gartner Research analyst Thilo Koslowski said the problem is that the transmission wasn't strong enough to handle the torque the engine was producing.
In a way, it's a good problem to have, he said.
"It's pretty impressive that the car has so much torque, because it means the experience, when customers are driving around in the car, will be what drivers are used to with internal combustion engines," he said last month. "It's good to see an electric engine can create so much torque."
But of course, there are obvious downsides as well, Koslowski said.
"As the company gets closer to getting into the market, I think it is realizing that some of its claims aren't coming to [reality,]" he said. "It's a major problem they have to solve of the car will be useless. They've already admitted they will have to replace the transmission. These are little things that larger companies could handle differently, because they have economies of scale, while for Tesla, it will add extra cost."
Last month, Drori said the company planned to accelerate production until all 2008 orders are filled, but also expected to deliver some cars in early 2009.
On Thursday, Tesla said early production would proceed "at a limited rate" and then ramp up to full production when the permanent powertrain is ready later this year. Series production is scheduled to begin March 17, according to the announcement.
"We will produce as few early production Roadsters as is necessary, for obvious reasons," Siry said when asked about how many interim-transmission Roadsters Tesla planned to produce. "It all depends on when we get the permanent solution ready for production."
"Full production" will amount to at least 1,800 cars per year, he said.
Also on Thursday, Tesla announced that it received all the regulatory approvals it needs to import the first production Roadster for sale and that the first production car would arrive at the Tesla Motors headquarters next week for delivery to Tesla Chairman Elon Musk, the co-founder of PayPal and SpaceX who also is a Tesla investor.
The news comes along with several other electric-car announcements this week.
Project Better Place earlier this week announced it is partnering with Renault and Nissan Motor Co. to develop a battery-charging and -replacement network, first in Israel and then around the world (see press release). The startup last year raised $230 million for its plan to lease removable batteries for electric cars and build a network of battery-charging and replacement centers around the globe (see Project Better Place Tops Off and New Choices At the Pump: Battery Recharge or Replacement).
And Electrovaya, a lithium-ion battery company, also launched a low-speed electric vehicle this week, called Maya-300, after last week announcing a partnership with Malcolm Bricklin's Visionary Vehicles (see this Clean Break post, which also discusses EEStor, an ultracapacitor startup that last week announced a deal with Lockheed Martin).