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The Tesla Roadster is a battery electric vehicle (BEV) sports car produced by the electric car firm Tesla Motors in California. The Roadster is the only highway-capable electric vehicle in serial production (as opposed to prototype or evaluation fleet production) in North America or Europe. Tesla had produced more than 1,200 Roadsters sold in at least 28 countries as of July 2010. Tesla began producing right-hand-drive Roadsters in early 2010 for the British Isles, Australia, Japan, Hong Kong and Singapore.

The Roadster is the first production automobile to use lithium-ion battery cells and the first production BEV (all-electric) to travel more than 200 miles (320 km) per charge. The world distance record of 501 km (311 mi) for a production electric car on a single charge was set by a Roadster on October 27, 2009 during the Global Green Challenge in outback Australia. In March 2010, a Tesla Roadster became the first electric vehicle to win the Monte Carlo Alternative Energy Rally and the first to win any Federation Internationale de l'Automobile-sanctioned championship when a Roadster driven by Formula One driver Erik Comas beat 96 competitors for range, efficiency and performance in the three-day, nearly 1,000-kilometer challenge.

According to an independent analysis from the U.S. EPA, the Roadster can travel 244 miles (393 km) on a single charge of its lithium-ion battery pack, and can accelerate from 0 to 60 mph (0 to 97 km/h) in 3.7 seconds. The Roadster's efficiency, as of September 2008, was reported as 120 mpg-ge (2.0 L/100 km). It uses 135 Wh/km (21.7 kWh/100 mi or 490 kJ/km) battery-to-wheel, and has an efficiency of 92% on average.

The Roadster has a net base price of US$101,500 after a $7,500 U.S. federal tax credit is discounted ($109,000 MSRP price), and there are other tax credits and incentives in several states. The Roadster has a base price of £86,950 in the UK and €84,000 in continental Europe. As an electric vehicle, the Roadster also qualifies for several government incentives throughout Europe

History

The car was officially unveiled to the public on July 19, 2006, in Santa Monica, California, at a 350-person invitation-only event held in Barker Hangar at Santa Monica Airport.

The San Francisco International Auto Show, held on November 18–26, 2006, was the Tesla Roadster's first auto show. Tesla Roadsters have been featured in numerous subsequent auto shows, including international shows in Los Angeles, Detroit and Frankfurt.

The first Tesla Roadster was delivered in February 2008 to Tesla co-founder, chairman and product architect Elon Musk. The company produced 500 similar vehicles through June 2009. In July 2009, Tesla began production of its 2010 model-year Roadster—the first major product upgrade since Tesla began production in 2008. Simultaneously, Tesla began producing the Roadster Sport, the first derivative of Tesla's proprietary, patented powertrain. The car accelerates from 0 to 60 mph in 3.7 seconds, compared to 3.9 seconds for the standard Roadster. Changes for the 2010 model-year cars include:

Beginning mid-March 2010, Tesla Motors, in an effort to show off the practicality of its electric cars, sent one of its Roadsters around the world. Starting at the Geneva autoshow, the roadster will travel until its arrival at the Paris Autoshow on September 28, 2010.

In July 2010, Tesla introduced the "Roadster 2.5," the latest update of the Roadster. New features in Roadster 2.5 include:

The Roadster is the most expensive prize ever offered on The Price Is Right, $112,845, in a playing of Green Road on April 22, 2010. A Roadster is used as a promotional tool for sustainable energy.

Development

The Roadster was developed by Tesla Motors to mass produce AC Propulsion's tzero concept car. The production idea was conceived by Martin Eberhard and Marc Tarpenning who incorporated Tesla Motors in Delaware on July 1, 2003 to pursue the idea commercially. South African-born entrepreneur Elon Musk took an active role within the company starting in 2004, including investing US$7.5 million, overseeing Roadster product design from the beginning, and greatly expanding Tesla's long-term strategic sales goals to include developing mainstream vehicles after the sports car. Musk became Tesla's Chairman of the Board in April, 2004 and had helped recruit JB Straubel as chief technology officer in March, 2004. Musk received the Global Green 2006 product design award for the design of the Tesla Roadster, presented by Mikhail Gorbachev, and he received the 2007 Index Design award for the design of the Tesla Roadster.

Before Tesla had developed the Roadster's proprietary powertrain, the company licensed AC Propulsion's EV Power System design and Reductive Charging patent which covers integration of the charging electronics with the inverter, thus reducing mass, complexity, and cost. Tesla then designed and built its own power electronics, motor, and other drivetrain components that incorporated this licensed technology from AC Propulsion. Given the extensive redevelopment of the vehicle, Tesla Motors no longer licenses any proprietary technology from AC Propulsion. The Roadster's powertrain is unique.

On 11 July 2005, Tesla and British sports car maker Lotus entered an agreement about products and services based on the Lotus Elise, where Lotus provided advice on designing and developing a vehicle as well as producing partly assembled vehicles, and amended in 2009, helped with basic chassis development. The Roadster has a parts overlap of roughly 6 percent with the Lotus Elise. Tesla's designers chose to construct the body panels using resin transfer molded carbon fiber composite to minimize weight; this choice makes the Roadster one of the least expensive cars with an entirely carbon fiber skin.

Several prototypes of the Tesla Roadster were produced from 2004 through 2007. Initial studies were done in two "test mule" vehicles based on Lotus Elises equipped with all-electric drive systems. Ten Engineering Prototypes (EP1 through EP10) which led to many minor changes were then built and tested in late 2006 and early 2007. Tesla then produced at least 26 Validation Prototypes (VP1 through VP26) which were delivered beginning in March, 2007. These final revisions were endurance and crash tested in preparation for series production.

In August 2007, Martin Eberhard was replaced by an interim CEO, Michael Marks. Marks accepted the temporary position while a recruitment drive went into place. In December 2007, Ze'ev Drori became the CEO and President of Tesla Motors. In October 2008, Musk succeeded Ze'ev Drori as CEO. Drori became Vice Chairman and left the company in December. In January, 2008, the NHTSA announced that it would grant a waiver of the advanced air bag rule noting that the Tesla Roadster already includes standard air bags; similar waivers have been granted to many other small volume manufacturers as well, including Lotus, Ferrari, and Bugatti. Tesla delivered its first production car in February 2008 to Musk.

Tesla announced in early August 2009 that Roadster sales had resulted in overall corporate profitability for the month of July 2009. The company said it earned approximately US$1 million on revenue of US$20 million. Profitability arose primarily from improved gross margin on the 2010 Roadster, the second iteration of Tesla’s award-winning sports car. Tesla, which like all automakers records revenue when products are delivered, shipped a record 109 vehicles in July and reported a surge in new Roadster purchases.

Tesla, which signed a production contract with Group Lotus in 2007 to produce "gliders" for the Roadster, announced in early 2010 that Roadster production would continue until early 2012, in part due to tooling changes at Lotus' assembly plant in the UK.

Production

Tesla cumulative production of the Roadster reached 1,000 cars in January 2010. The Roadster is an American car with a vehicle identification number common to all cars considered American manufactured, but it has parts from around the world. The body panels come from French supplier Sotira. These are sent from France to Hethel, U.K., where Tesla contracts with Lotus to build the Roadster's unique chassis. The Roadster shares roughly 6 percent of its components with the Lotus Elise; shared components include the windshield, air bags, some tires, some dashboard parts, and suspension components. The Roadster's single-speed gearbox is made in Detroit to Tesla's specifications by Auburn Hills, Michigan-based supplier Borg Warner. Brakes and airbags are made by Siemens in Germany, and some crash testing was conducted at Siemens as well.

For Roadsters bound for customers in North America, the chassis is then sent to Menlo Park, California, for final assembly. For Roadsters bound for customers in Europe or elsewhere outside of North America, the chassis is sent to a facility near Hethel, U.K., for final assembly. At these final assembly locations, Tesla employees install the entire powertrain, which consists of the battery pack, power electronics module, gearbox and motor. Tesla also performs rigorous "pre-delivery inspection" on every car before customers take ownership.

On 22 March 2010, Tesla ordered a minimum of 2,400 units from Lotus until 31 December 2011.

History of production

Subsequent to completion of production car number one at Hethel, the company announced problems with transmission reliability. The development transmission, with first gear enabled to accelerate 0 to 60 mph (0 to 97 km/h) in 4 seconds, was reported to have a life expectancy of as low as only a few thousand miles. Tesla Motors' first two transmission suppliers were unable to produce transmissions, in quantity, that could withstand the gear-shift requirements of the high torque, high rpm electric motor. In December, 2007, Tesla Motors announced plans to ship the initial Roadsters with the transmissions locked into second gear to provide 0 to 60 mph (0 to 97 km/h) acceleration in 5.7 seconds. The first production car was not delivered with this interim solution; P1 has both transmission gears enabled. According to the plan, the initial transmissions will be swapped out under warranty when the finalized transmission, power electronics module (PEM), and cooling system becomes available. The EPA range of the car was also restated downward from 245 to 221 miles (394 to 356 km). The downward revision was attributed to an error in equipment calibration at the laboratory that conducted the original test.

Sales

Tesla had delivered more than 1,200 cars to customers in more than 25 countries by July 2010. Tesla CEO, Chairman and Product Architect Elon Musk said in June 2009 that the company would begin producing a right-hand-drive version of the car in 2010. The base price for the 2010 models, which began shipping to customers in July 2009, was US$109,000. The Roadster has a bumper-to-bumper 3-year, 36,000-mile (58,000 km) warranty. Tesla also offers an extended powertrain warranty and a battery replacement warranty. Options ranging from colors to audio to high-power connectors for faster charging will increase the price.

In July 2009, Tesla announced that US consumers could finance the Roadster through Bank of America. Financing is available for up to 75 percent of the total vehicle purchase price. A customer approved for a 5-year financing term on a base Roadster could put down as little as $20,000 before taxes and net of the US federal tax credit. The monthly payment would be approximately $1,700 at a 5 percent annual percentage rate (APR). That monthly payment is typical for high performance, although the Roadster costs roughly $4 to refuel and does not require routine oil changes or exhaust system work. Unlike internal combustion engines, Teslas get a 100 percent waiver on sales, luxury and use taxes in at least four states, and they qualify for commuter lane privileges, free parking and free charging in many regions.

Tesla sells Roadsters directly to customers. It sells online, in 13 showrooms and over toll-free phone lines in North America and Europe. Tesla does not operate through franchise dealerships but operates company-owned stores. The company has said that it takes its retail cues from Apple, Starbucks and other non-automotive retailers.

Outside the United States

The company has been shipping cars to European customers since the summer of 2009. Tesla sold out of its EU special-edition vehicle, which had a 2010 model-year production run of 250 cars, with a base price of €99,000.

Tesla opened a showroom in London, its first outside the US, on June 25, 2009, and announced at the same time that it would start building right-hand-drive models from early 2010. Tesla opened a store in Munich in September 2009 and a store in Monaco in November 2009. It opened stores in Zurich and Copenhagen in the summer of 2010. Reservations for the 2010 Roadster are available for a 3,000 Euro refundable reservation fee.

Service

Electric vehicles require much less service and maintenance than internal combustion engine vehicles. They do not require routine oil changes. They do not have any tailpipe emissions and therefore do not require any muffler or exhaust system work. They do not require replacement spark plugs, pistons, hoses or belts. The conventional parts of the car—including the brakes, body work and any interior and HVAC work—can be performed by any qualified automotive technician, exotic car garage or other local provider.

Tesla recommends that customers bring their car to a service center for an antifreeze change every five to seven years. Tesla's website recommends the owner bring the vehicle in for service "once a year or every 12,000 miles". For other concerns with Tesla's all-electric powertrain, Tesla has created a "mobile service unit" that dispatches company-trained technicians to customers' homes or offices in case the owner is experiencing problems. Tesla charges the customer according to the distance the service unit needs to travel: one US dollar per mile roundtrip with a 100 dollar minimum. Technicians drive company vans equipped with numerous tools and testing equipment to do "in the field" repairs, enhancements and software upgrades. Tesla debuted its "house call" approach in the spring of 2009, when the company announced a recall due to a manufacturing problem in the Lotus assembly plant, which also affected the Lotus Elise and other models from the British sports car maker.

The first Tesla Motors service center, in Los Angeles, California, was opened on Santa Monica Boulevard on May 1, 2008. Tesla Motors publicly opened their second showroom and service area in Menlo Park, California on July 22, 2008. The Menlo Park location is also the final assembly area for Tesla Roadsters. Tesla also operates service centers in New York City, Miami, Florida, Chicago, Illinois and Seattle, Washington.

Tesla plans to build additional service centers over the next few years to support sales of its next vehicle, the Model S sports sedan. Planning is underway for an additional 15 service centers in United States major metropolitan locations. Possible locations for sales and service locations in Europe were announced in a letter to customers in May, 2008.

Specifications

Motor

The roadster is powered by a 3-phase, 4-pole electric motor, producing a maximum net power of 248 hp (185 kW). Maximum torque is 200·ft-lbf (270 N·m), obtained at 0 rpm and almost constant up to 6,000 rpm, a common feature of electric motors and one of the biggest differences (from the performance point of view) with internal combustion engines. The motor is air-cooled and does not need a liquid cooling system. The Sport Model introduced during the 2009 Detroit Auto Show includes a motor with a higher density, hand-wound stator that produces a maximum of 288 hp (215 kW). Both motors are designed for rotational speeds of up to 14,000 rpm, and the regular motor delivers an efficiency of typically 90%, or 80% at peak power. It weighs less than 70 pounds.

Transmission

Starting in September, 2008 Tesla Motors selected BorgWarner to manufacture gearboxes and began equipping all Roadsters with a single speed, fixed gear gearbox (8.2752:1) with an electrically actuated parking lock mechanism and a mechanical lubrication pump.

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 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. 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. The upgraded system also improved the maximum torque from 200 to 280 ft·lbf (270 to 380 N·m) and improves the Roadster's quarter mile times.

Performance

The Roadster's 0 to 60 mph (0–97 km/h) acceleration time is 3.9 seconds for the Standard Model and 3.7 seconds for the 2010 Sport Model. MotorTrend, which performed the first independent instrumented testing of the Roadster Sport, confirmed the company's reported 0 to 60 mph time of 3.7 seconds (MotorTrend recorded 0 to 60 mph of 3.70 seconds; it recorded a quarter-mile test at 12.6 sec @ 102.6 mph). The top speed is electronically limited to 125 mph (201 km/h). The Roadster covers the quarter-mile drag strip in 12.757 seconds at 104.74 mph (168.56 km/h). It weighs about 2,700 lb (1,200 kg) and is rear wheel drive; most of the car's weight is centered in front of the rear axle. Its body style and smooth underbody result in a Cd of 0.35.

Tesla began delivering the higher performance Sport version of the Roadster in July 2009. The Roadster Sport has adjustable dampers and a new hand-wound motor, capable of 0 to 60 mph (0 to 97 km/h) in 3.7 seconds. Scotty Pollacheck, a high-performance driver for Killacycle, drove a 2010 Tesla Roadster Sport at the Wayland Invitational Drag Race in Portland, Ore., in July 2009. He did a quarter-mile (~400 m) in dry conditions in 12.643 seconds, setting a new record in the National Electric Drag Racing Association among the SP/A3 class of vehicles.

The EPA combined range (specifying distance traveled between charges) measured in February 2008 for early production Roadsters was 231 mi (372 km) city, 224 mi (360 km) highway, and 227 mi (365 km) combined (city/highway). In August 2008, additional testing with the newer Powertrain 1.5 resulted in an EPA combined range of 244 mi (393 km). The vehicle set a new distance record when it completed the 241-mile (388 km) Rallye Monte Carlo d'Energies Alternatives with 36 miles (58 km) left on the charge.

Simon Hackett and Emilis Prelgauskas broke the distance record for an electric vehicle, driving 501 km (311 miles) from Alice Springs to Marla, South Australia, in Simon's Tesla Roadster. The car had about 4.8 km (three miles) of range left when the drive was completed.

Battery system

Tesla Motors refers to the Roadster's battery pack as the Energy Storage System or ESS. The ESS contains 6,831 lithium ion cells arranged into 11 "sheets" connected in series; each sheet contains 9 "bricks" connected in series; each "brick" contains 69 cells connected in parallel (11S 9S 69P). The cells are 18 mm (0.71 in) in diameter and 65 mm (2.6 in) long (18650 form-factor); this type of lithium-ion cell is also found in most laptop computer batteries. The pack is designed to prevent catastrophic cell failures from propagating to adjacent cells, even when the cooling system is off. Coolant is pumped continuously through the ESS both when the car is running and when the car is turned off if the pack retains more than a 90% charge. The coolant pump draws 146 watts.

A full recharge of the battery system requires 3½ hours using the High Power Connector which supplies 70 amp, 240 volt electricity; in practice, recharge cycles usually start from a partially charged state and require less time. A fully charged ESS stores approximately 53 kWh of electrical energy at a nominal 375 volts and weighs 992 lb (450 kg).

Tesla Motors stated in February 2009 that the current replacement cost of the ESS is slightly under USD$36,000, with an expected life span of 7 years/100,000 mi (160,000 km), and began offering owners an option to pre-purchase a battery replacement for USD$12,000 today with the replacement to be delivered after seven years. The ESS is expected to retain 70% capacity after 5 years and 50,000 miles (80,000 km) of driving (10,000 miles (16,000 km) driven each year). Tesla Motors provides a 3 year/36,000 mile warranty on the Roadster with an optional 4 year/50,000 mile extended warranty available at an "additional cost" (2008 Roadster buyers received the 4/50 extension at no cost while later purchasers need to pay). A non-ESS warranty extension is available for USD$5,000 and adds another 3/36 to the coverage of components, excluding the ESS, for a total of 6 years/72,000 mi (120,000 km).

Tesla Motors announced plans to sell the battery system to TH!NK and possibly others through its Tesla Energy Group division. The TH!NK plans were put on hold by interim CEO Michael Marks in September, 2007. Think now obtains their Lithium-Ion batteries from Enerdel.

Recharging

The Tesla Roadster uses a unique charging connector, although Tesla has indicated they will convert to the SAE J1772 standard. The vehicle can be recharged using:

Charging times vary depending on available voltage and amperage. In a best case scenario Tesla claims a recharge time of approximately 4 hours using 240v and a 90 amp breaker and a worst case of 48 hours using 120v and a 15 amp breaker.

The Tesla Roadster is increasingly popular on circuits throughout Europe, including the UK's Crystal Palace.
Interior
A Tesla Roadster in Barcelona.
Tesla on display at the 2010 Canadian International Autoshow in Toronto
Rear view of the vehicle
Connected power supply.