Tesla Roadster

Tesla Roadster
Tesla Roadster Sport 2.5
Overview
Manufacturer	Tesla Motors
Also called	Code name: DarkStar
Production	2008–2012
Assembly	Hethel, United Kingdom Menlo Park, California, U.S.
Designer	Tesla Motors
Body and chassis
Class	Roadster
Body style	2-door roadster
Layout	Rear mid-engine, rear-wheel drive
Related	Lotus Elise
Powertrain
Electric motor	1.5, 2.0 248 hp (185 kW), 200 lb·ft (270 N·m), 3-phase 4-pole; 2.5 Non-Sport 288 hp (215 kW), 273 lb·ft (370 N·m), 3-phase 4-pole; 2.5 Sport 288 hp (215 kW), 295 lb·ft (400 N·m), 3-phase 4-pole AC induction motor
Transmission	Single speed BorgWarner fixed gear (8.27:1 ratio)
Battery	53 kWh (lithium-ion battery at the pack level: 117 Wh/kg and 370 Wh/L) CAC (Capacity) approx. 160 Ah when new
Electric range	244 mi (393 km) using EPA combined cycle
Plug-in charging	Proprietary inlet, 16.8 kW (70 A 240 V) with HPWC outlet and with the SAE J1772-2009 adapter, adapters for domestic AC sockets
Dimensions
Wheelbase	2,352 mm (92.6 in)
Length	3,946 mm (155.4 in)
Width	1,873 mm (73.7 in)
Height	1,127 mm (44.4 in)
Curb weight	1,305 kg (2,877 lb)

The Tesla Roadster is a battery electric vehicle (BEV) sports car that was produced by the electric car firm Tesla Motors in California from 2008 to 2012. The Roadster is the first highway-capable all-electric vehicle in serial production for sale in the United States in recent times. A replacement for the Roadster is expected for 2019.

Tesla sold about 2,450 Roadsters in over 30 countries, and most of the last Roadsters were sold in Europe and Asia during the fourth quarter of 2012. Tesla produced right-hand-drive Roadsters from early 2010. The Roadster base price in 2010 was US$109,000 in the United States, GB£86,950 in the United Kingdom, A$191,888 in Australia, and €84,000 in continental Europe. As an electric vehicle, the Roadster qualified for several government incentives in many nations.

The Roadster was 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 which it averaged a speed of 25 mph (40 km/h). 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 former Formula One driver Érik Comas beat 96 competitors for range, efficiency and performance in the three-day, nearly 1,000-kilometer (620 mi) challenge.

According to 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 or 3.9 seconds depending on the model. The Roadster's efficiency, as of September 2008, was reported as 120 MPGe (2.0 L/100 km). It uses 135 Wh/km (21.7 kW·h/100 mi, 13.5 kW·h/100 km or 490 kJ/km) battery-to-wheel, and has an efficiency of 88% on average.

History

The car was officially revealed 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.

A Roadster running at the Goodwood Festival of Speed

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 (0 to 97 km/h) in 3.7 seconds, compared to 3.9 seconds for the standard Roadster. Changes for the 2010 model-year cars include:

• An upgraded interior and push-button gear selector, including "executive interior" of exposed carbon fiber and premium leather, and clear-coat carbon fiber body accents.
• Locking, push-button glove box wrapped in leather.
• A centrally mounted video display screen to monitor real-time data, including estimated range, power regenerated, and the number of barrels of oil saved. This screen is visible to the driver and passenger.
• Adjustable, custom-tuned suspension. The shock absorbers' response and anti-sway bars are manually adjustable.
• More powerful and immediate heating, ventilation and air-conditioning.
• More efficient motor and hand-wound stator. The increase in efficiency allows the motor to deliver higher peak power.
• A suite of sound-deadening measures to dramatically reduce noise, vibration and harshness. For instance, engineers added pellets to a member of the chassis side rail. These pellets expand by 50 times original volume during the adhesive heating cycle to eliminate rattles.

All of these features, except for the motor were available either as standard or as add-on option for the non-sport model.

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 auto show, the Roadster completed its journey upon its arrival in Paris 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:

• A new look, which included a new front fascia with diffusing vents, and rear diffuser reflecting the future of Tesla design
• Directional forged wheels available in both silver and black
• New seats with improved comfort, larger more supportive bolsters and a new lumbar support system
• Power control hardware that enables spirited driving in exceptionally hot climates
• An optional 7" touchscreen display with back-up camera
• Improved interior sound reduction including new front fender liner material to make the cabin quieter

At the time, the Roadster was the most expensive single prize ever offered on The Price Is Right, in a playing of Golden Road on April 22, 2010 in celebration of Earth Day. It was not won—according to the show, its price was over US$112,000.

A Roadster was used as a promotional tool for a wind power electricity company in 2012.

Tesla produced the Roadster until January 2012, when its supply of Lotus gliders ran out, as its contract with Lotus Cars for 2,500 gliders expired at the end of 2011. Tesla stopped taking orders for the Roadster in the U.S. market in August 2011. The next generation is expected to be introduced by 2018 and will not be based on the Lotus gliders but instead on a shortened version of the architecture developed for the Tesla Model S. Featuring new options and enhanced components, the 2012 Tesla Roadster is being sold in limited numbers only in Europe, Asia and Australia. Tesla's U.S. exemption for not having special two-stage passenger airbags expired for cars made after the end of 2011 so the last Roadsters could not be sold in the American market. Also a total of 15 Final Edition Roadsters were produced to close the manufacturing cycle of Tesla's first electric car. As of June 2012 the Roadster remained on sale in Europe and Asia and as of December 2012, inventories were not yet depleted.

Tesla announced an optional upgrade to current Roadsters, the Roadster 3.0 in December 2014. It will have a new battery pack from LG Chem, with capacity increased by 31% to 70kWh, a new aero kit designed to reduce drag, and new tires with lower rolling resistance.

In 2015, Musk suggested a new generation of Roadster in 2019, capable of faster acceleration.

Development

See also: Tesla motors § History

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 by using the sports car to fund development of mainstream vehicles. 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.

Frontal and rear views of the 2008 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.

External images
Tesla Roadster and Lotus Elise
Black Roadster and grey Elise

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 was undertaken. 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 U.S. National Highway Traffic Safety Administration (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" (complete cars minus electric powertrain) 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

Interior of Roadster 2.5 from July 2010

Tesla cumulative production of the Roadster reached 1,000 cars in January 2010. The Roadster is considered an American car though many carry a Vehicle Identification Number beginning with the letter "S" which is the designation for the United Kingdom. Some however carry a number starting with "5" appropriate to the US. Parts were sourced 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 BorgWarner. 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 at Wymondham near Hethel, 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.

Tesla ordered 2,500 gliders from Lotus, which ended supplies in December 2011 when their contract expired. Tesla ended production of the Roadster in January 2012.

Timeline

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 were to be swapped out under warranty when the finalized transmission, power electronics module (PEM), and cooling system became 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.

• During the first two months of production, Tesla produced a total of three Roadsters (P3/VINF002, P4/VINF004, and P5/VINF005). Production car # 1 (P1) and P2 were built prior to the start of regular series production, which began March 17, 2008.
• By September 10, 2008, Tesla had delivered 27 of the cars to customers. It was also reported that a newer, better transmission had been developed and that production of the car was hoped to reach 20 per week by December 2008, and 40 per week by March 2009. Over the next 20 days, however, only 3 more cars had been delivered to customers which brought the total to 30 as of September 30, 2008.
• By November 19, 2008, more than 70 of the cars had been delivered to customers.
• By December 9, 2008, the 100th car had been delivered to its customer.
• By February 11, 2009, 200 Roadsters had been produced.
• By April 2, 2009, 320 Roadsters had been delivered.
• In May 2009, Tesla issued a safety recall for all 345 of its Roadsters that were manufactured before April 22, 2009. Tesla sent technicians to customers' homes to tighten the rear, inner hub flange bolts. Tesla Motors told customers that without this adjustment, the driver could lose control of the car and crash. The problem originated at the Lotus assembly line that builds the Roadster and Lotus is also recalling some of its own vehicles. Tesla reminded customers that millions of cars are recalled every year.
• By the end of May 2009, the 500th Roadster had been delivered.
• Tesla made its first profit ever in July 2009, when it shipped 109 vehicles, the most ever so far for a single month.
• By September 15, 2009, 700 Roadsters had been delivered.
• Tesla announced on January 13, 2010, that it had produced its 1,000th Roadster. The company has delivered vehicles to customers in 43 states and 21 countries worldwide. In 2009 Tesla began taking orders from customers in Canada, and Canadian deliveries began in February 2010.
• In January 2010, Tesla began producing its first right-hand-drive Roadsters for the UK and Ireland. The 2010 model-year right-hand-drive Roadster includes a suite of unique noise-reduction materials and an upgraded sound system. The Roadster starts at £86,950 and costs about 1.5p per mile.
• On 29 January 2010, in a Form S-1 filing of its preliminary prospectus with the U.S. Securities and Exchange Commission, the company stated that it would halt production of the Roadster in 2011 and replace it with a new model which would not be introduced until 2013 at the earliest: "...we do not plan to sell our current generation Tesla Roadster after 2011 due to planned tooling changes at a supplier for the Tesla Roadster, and we do not currently plan to begin selling our next generation Tesla Roadster until at least one year after the launch of the Model S, which is not expected to be in production until 2012..."
• On 16 March 2010, Tesla Motors announced that it had "negotiated agreements with key suppliers that will increase total Roadster production by 40 percent and extend sales into 2012", also indicating that it would expand into the Asian and Australian markets by 2011.
• On 2 December 2010, Tesla had delivered more than 1,400 Roadsters.
• On 28 September 2011, Tesla delivered its 100th Roadster in Switzerland.
• Production ended in January 2012 and no longer available for sale the U.S. after December 2011.
• More than 2,418 units were sold worldwide through September 2012. The remaining cars were available for sale only in Europe and Asia.
• Most of the remaining Tesla Roadsters were sold during the fourth quarter of 2012.
• Tesla Motors had built approximately 2,600 Roadsters by the conclusion of its production.
• In 2015, it was announced that a successor to the Roadster would debut in 2019.

Special final edition

Tesla produced a special edition of 15 Final Edition Roadsters to close the production cycle of the electric car. The 15 special edition cars will be sold in each of the three sales regions, North America, Europe and Asia, and five units will be allocated to each. The Final Edition Roadster does not have any performance modifications, but features sporting atomic red paint, a duo of dark silver stripes on its hood and rear clamshell, and exclusive anthracite aluminum wheels.

Sales

Tesla delivered approximately 2,450 Roadsters worldwide between February 2008 and December 2012. Featuring new options and enhanced features, the 2012 Tesla Roadster was sold in limited numbers only in Mainland Europe, Asia and Australia, and as of July 2012, less than 140 units were available for sale in Europe and Asia before the remaining inventory would be sold out. Tesla's US exemption for not having special two-stage passenger airbags expired for cars made after the end of 2011 so the last Roadsters were not sold in the American market due to regulatory reasons.

There were fewer than 50 Total right-hand drive models of the Tesla Roadster produced and hand built in the UK.

Roadster with California's Clean Air Vehicle stickers (at the extremes of the bumper) that allows access to HOV lanes with solo driver

United States

The base price for the 2010 models, which began shipping to customers in July 2009, was US$109,000. The Roadster had a 3-year, 36,000-mile (58,000 km) warranty. Tesla also offered an extended powertrain warranty and a battery replacement warranty.

In July 2009, Tesla announced that US consumers could finance the Roadster through Bank of America. Financing was available for up to 75 percent of the total vehicle purchase price.

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

A Tesla Roadster on public display at a Japan-based showroom. It is also being charged.

Outside the United States

The company has been shipping cars to European customers since mid-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. A total of 575 units have been sold in Europe through October 2012.

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 and in Milan in February 2011. Reservations for the 2010 Roadster were available for a €3,000 refundable reservation fee.

As of 8 May 2012, Hansjoerg von Gemmingen of Karlsruhe / Germany drove his Tesla Roadster 205,711 kilometers (127,823 miles) in four years, this being the mileage world record for all-electric vehicles.

Kevin Yu, the director of Tesla Motors Asia Pacific, said that Roadsters were sold in Japanese showrooms at an average price between ¥12.8 million and ¥20 million. Japanese buyers are liable for additional yearly taxes due to the fact that the Roadster exceeds Japanese Government dimension regulations in the width category.

Howmanyleft.co.uk documents just 17 Tesla Roadster Sports and 31 Standard roadster models were declared on the road in the UK Q1 2015 making this little roadster extremely rare on UK roads.

Service

A Tesla Roadster taxi used by Oslo Taxi in Oslo, Norway.

Whereas vehicles with internal combustion engines require more frequent service for oil changes and routine maintenance on engine components and other related systems, 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, Chicago, and Seattle.

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

Tesla Roadster with hood and trunk open

The Roadster is powered by a 3-phase, 4-pole, induction electric motor with a maximum output power of 248 hp (185 kW). Its maximum torque of 200 lb·ft (270 N·m) is immediately available and remains constant from 0 to 6,000 rpm; nearly instantaneous torque is a common design feature of electric motors and offers one of the biggest performance differences from 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 a typical efficiency of 88% or 90%; 80% at peak power. It weighs less than 70 pounds (32 kg).

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 pawl 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 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. 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 lb·ft (270 to 380 N·m) and improves the Roadster's quarter mile times.

Gear selector

In the interior the gear selector is similar to a push-button automatic with buttons labeled P, R, N and D while some earlier models have a gear lever similar to that in cars with manual transmission.

Performance

The Roadster's 0 to 60 mph (0 to 97 km/h) acceleration time is 3.9 seconds for the Standard Model and 3.7 seconds for the 2010 V2.5 Sport Model. MotorTrend, which performed the first independent instrumented testing of the Roadster Sport, confirmed the company's reported 0 to 60 mph (0 to 97 km/h) time of 3.7 seconds. MotorTrend recorded 0 to 60 mph (0 to 97 km/h) of 3.70 seconds; it recorded a test at 12.6 sec giving 102.6 mph (165.1 km/h). The top speed is electronically limited to 125 mph (201 km/h). The Roadster covers the dragstrip in 12.757 seconds at 104.74 mph (168.56 km/h). It weighs 2,877 lb (1,305 kg) and is rear wheel drive; most of the car's weight is centered in front of the rear axle. Its body style results in a drag coefficient of Cd=0.35–0.36. It has a rolling resistance of Crr=0.011.

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, Oregon, 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 mi) from Alice Springs to Marla, South Australia, in Simon's Tesla Roadster. The car had about 4.8 km (3.0 mi) of range left when the drive was completed.

Battery system

An electrical plug of the Tesla Roadster Sport

The rear side of a Tesla Roadster battery pack

The charging screen of a Tesla Roadster Sport

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 of the 18650 form-factor commonly found in laptop batteries. Sources disagree on the exact type of Li-Ion cells—GreenCar says lithium cobalt oxide (LiCo), while researchers at DTU/INESC Porto state lithium manganese oxide (LMO). LiCo has higher reaction energy during thermal runaway than LMO.

The pack is designed to prevent catastrophic cell failures from propagating to adjacent cells (thermal runaway), 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 US$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 US$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). However, a July 2013 study found that even after 100,000 miles, Roadster batteries still have 80%–85% capacity and the only significant factor is mileage (not temperature) 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 US$5,000 and adds another 3/36 to the coverage of components, excluding the ESS, for a total of 6 years for 72,000 mi (116,000 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. TH!NK now obtains their Lithium-Ion batteries from Enerdel.

If the battery is allowed to become completely discharged it will be irretrievably damaged and the only option is to replace it at a cost of $40,000. Neither insurance nor warranty will cover this cost; it has to be met out of the owner's own pocket. (see also Brick (electronics)) The likelihood of this occurring is extremely rare however as the vehicle also has onboard telemetry and a live GSM connection to Tesla so that the owner can be alerted well in advance of any damage occurring (There has only been 1 recorded example of this). The roadster can also be set up with systems such as Open Vehicle Monitoring System (OVMS) that also allows the owner to remotely access the vehicle telemetry and activate battery charging via android or iPhone devices.

Tesla charging unit

Recharging

The Tesla Roadster uses a proprietary charging connector, although Tesla sells a mobile adapter that enables recharging with an SAE J1772-2009 connector. The vehicle can be recharged using:

• A wall-mounted 208–240 V, 70 A maximum current Home Connector. This appears to be an OEM version of the TS-70 charging station from ClipperCreek.
• A portable 120–240 V, 40 A maximum current Universal Mobile Connector cable that can plug into a NEMA 14–50 receptacle and other 240V receptacles using adapters.
• A portable 120 V, 15 A maximum current Spare Mobile Connector cable that plugs into a standard North American domestic socket.

Charging times vary depending on the ESS's state-of-charge, the available voltage, and the available circuit breaker amp rating (current). In a best case scenario using a 240 V charger on a 90 A circuit breaker, Tesla documents a recharging rate of 56 miles (90 km)-of-range for each hour charging; a complete recharge from empty would require just under 4 hours. The slowest charging rate using a 120V outlet on a 15 A circuit breaker would add 5 miles (8.0 km)-of-range for each hour charging; a complete recharge from empty would require 48 hours.

Energy efficiency

In June 2006, Tesla Motors reported the Roadster's battery-to-wheel efficiency as 110 W·h/km (17.7 kW·h/100 mi) on an unspecified driving cycle—either a constant 60 mph (97 km/h)) or SAE J1634 test—and stated a charging efficiency of 86% for an overall plug-to-wheel efficiency of 128 W·h/km (20.5 kW·h/100 mi).

Evolution of the Roadster's plug-to-wheel efficiency (smaller values indicate better efficiency)

In March 2007, Tesla Motors reported the Roadster's efficiency on the EPA highway cycle as "135 mpg [U.S.] equivalent, per the conversion rate used by the EPA" or 133 W·h/km (21.5 kW·h/100 mi) battery-to-wheel and 155 W·h/km (24.9 kW·h/100 mi) plug-to-wheel. The official U.S. window sticker of the 2009 Tesla Roadster showed an EPA rated energy consumption of 32 kW-hrs/100 mi in city and 33 kW-hrs/100 mi on the highway, equivalent to 105 mpg city and 102 mpg highway. The EPA rating for on board energy efficiency for electric vehicles before 2010 was expressed as kilowatt-hour per 100 miles (kW-hrs/100 mi). Since November 2010, with the introduction of the Nissan Leaf and the Chevrolet Volt, EPA began using a new metric, miles per gallon gasoline equivalent (MPGe). The Roadster was never officially rated by the EPA in MPGe.

In August 2007, Tesla Motors' dynamometer testing of a Validation Prototype on the EPA combined cycle yielded a range of 221 mi (356 km) using 149 W·h/km (23.9 kW·h/100 mi) battery-to-wheel and 209 Wh/km (33.6 kW·h/100 mi) plug-to-wheel.

In February 2008, Tesla Motors reported improved plug-to-wheel efficiency after testing a Validation Prototype car at an EPA-certified location. Those tests yielded a range of 220 mi (350 km) and a plug-to-wheel efficiency of 256 mpg_ge, or 199 W·h/km (32.1 kW·h/100 mi).

In August 2008, Tesla Motors reported on testing with the new, single-speed gearbox and upgraded electronics of Powertrain 1.5 which yielded an EPA range of 244 mi (393 km) and an EPA combined cycle, plug-to-wheel efficiency of 174 W·h/km, 630 kJ/km (28 kW·h/100 mi).

Roadster being tested through a driving cycle at Argonne National Laboratory's two-wheel dynamometer. These tests helped researchers develop test procedures to evaluate fuel efficiency in electric vehicles in 2010.

In 2007, the Roadster's battery-to-wheel motor efficiency was reported as 88% to 90% on average and 80% at peak power. For comparison, internal combustion engines have a tank-to-wheel efficiency of about 15%. Taking a more complete picture including the cost of energy drawn from its source, Tesla reports that their technology, assuming electricity generated from natural gas-burning power plants, has a high well-to-wheel efficiency of 1.14 kilometers per megajoule, compared to 0.202 km/MJ for gasoline-powered sports cars, 0.478 km/MJ for gasoline-powered commuter cars, 0.556 km/MJ for hybrid cars, and 0.348 km/MJ for hydrogen fuel cell vehicles.

Petroleum-equivalent efficiency

See also: electric car § Comparison with internal combustion engine vehicles (ICEVs)

The Roadster does not actually use gasoline; therefore, petroleum efficiency (MPG, L/100 km) cannot be measured directly but instead is calculated using one of several equivalent methods:

A number comparable to the typical Monroney sticker's "pump-to-wheel" fuel efficiency can be calculated based on regulations from the DOE and its energy content for a U.S. gallon of gasoline of 33,705 ​^Wh⁄_gal (also called the Lower Heating Value (LHV) of gasoline):

$\frac{33705\,\frac{\mathrm{Wh}}{\mathrm{gal_{ge}}}} {135\,\frac{\mathrm{Wh}}{\mathrm{km}} \times \frac{1.6\, \mathrm{km}}{\mathrm{mi}}} \times 77.6 \% {\mathrm{_{charging\ eff.}}}= 120 \,\mathrm{mpg_{ge}} = 1.95 \frac{\mathrm{L_{ge}}}{100\, \mathrm{km}}$

For CAFE regulatory purposes, the DOE's full petroleum-equivalency equation combines the primary energy efficiencies of the USA electric grid and the well-to-pump path with a "fuel content factor" that quantifies the value of conservation, scarcity of fuels, and energy security in the USA. This combination yields a factor of 82,049 ​^Wh⁄_gal in the above equation and a regulatory fuel efficiency of 293 mpg_geCAFE.

Tesla Roadster 2.5 charging from a conventional outlet

Recharging with electricity from the average USA grid, the factor changes to 12,307 ​^Wh⁄_galUS to remove the "fuel content factor" = ​¹⁄_0.15 and the above equation yields a full-cycle energy-equivalency of 44.0 mpg_{ge full-cycle}. For full-cycle comparisons, the sticker or "pump-to-wheel" value from a gasoline-fueled vehicle must be multiplied by the fuel's "well-to-pump" efficiency; the DOE regulation specifies a "well-to-pump" efficiency of 83% for gasoline. The Prius' sticker 46 miles per US gallon (5.1 L/100 km; 55 mpg_-imp), for example, converts to a full-cycle energy-equivalent of 38.2 mpg_full-cycle.

Recharging with electricity generated by newer, 58% efficiency CCGT power plants, changes the factor to 21,763 ​^Wh⁄_gal in the above equation and yields a fuel efficiency of 77.7 mpg_ge.

Recharging with non-fossil fuel electricity sources such as hydroelectric, solar power, wind or nuclear, the petroleum equivalent efficiency can be even higher as fossil fuel is not directly used in refueling.

Monetary cost offers another way to find an equivalent fuel efficiency. Tesla Motors reports an energy cost of approximately US 1.4¢ per mile when using PG&E's E-9A rate plan (off-peak night-time incentive charging) cost of 5.294¢ per kWh which is available in the two U.S. states covered by PG&E. Comparison with a gasoline price of US$4.00/ U.S. gallon, for instance, results in an equivalent of 270 mpg_ge using the E-9 rate or 123 mpg_ge using the USA average residential electricity price of 11.6¢ per kWh. Including the battery replacement cost at its warranty limit, the cost per mile increases and the equivalent miles per gallon are reduced. The time value of money, improving battery technology, and a 6–8% annual reduction in battery cost all lower the net present costs of battery replacement. These factors allow Tesla Motors to sell customers a replacement battery pack for US$12,000, to be installed after the 7-year/70,000 miles (110,000 km) lifespan of the original pack, resulting in a net battery cost of 17.1¢/mile. Adding this to the electricity costs of 1.4¢/mile above results in an overall cost equivalence of $4/gal ÷ 18.5¢/mile = 21.5 mpg_ge, which can be compared to conventional car ratings after transmission, engine, and other drivetrain replacement costs are factored into the mpg ratings for those cars.

Reviews

Tesla Roadster reviews can be grouped in two main categories: older reviews of "validation prototypes" (2006–2008), before Tesla began serial production and customer deliveries, and reviews on cars in serial production (2008–2010).

The global online auto review site Autoguide.com tested Tesla's fourth-generation car in October 2010. Autoguide editor Derek Kreindler said "The Tesla Roadster 2.5 S is a massively impressive vehicle, more spacecraft than sports car. Theories like global warming, peak oil and rising oil prices should no longer bring heart palpitations to car fans. The Tesla shows just how good zero-emissions "green" technology can be. Quite frankly, getting into a normal car at the end of the test drive was a major letdown. The whirr of the engine, the shove in the backside and the little roadster that seems to pivot around you is replaced by a grunting, belching, feedback-free driving experience". He continues on that "but for a $100,000 car, it could use some work" complaining of purposefully cheap work.

In the March 2010 print edition of British enthusiast magazine EVO (p. 120), editor Richard Meaden was the first to review the all-new right-hand-drive version of the Roadster. He said the car had "serious, instantaneous muscle". "With so much torque from literally no revs the acceleration punch is wholly alien. Away from traffic lights you'd murder anything, be it a 911 Turbo, GT-R or 599, simply because while they have to mess about with balancing revs and clutch, or fiddle with launch controls and invalid warranties, all you have to do is floor the throttle and wave goodbye".

In December 2009, Wall Street Journal editor Joseph White conducted an extended test-drive and determined that "you can have enormous fun within the legal speed limit as you whoosh around unsuspecting Camry drivers, zapping from 40 to 60 miles per hour in two seconds while the startled victims eat your electric dust". White, a Pulitzer Prize-winning journalist, praised the car's environmental efficiency but said consumer demand reflected not the environmental attributes of the car but its performance. "The Tesla turns the frugal environmentalist aesthetic on its head. Sure, it doesn't burn petroleum, and if plugged into a wind turbine or a nuclear plant, it would be a very low-carbon machine. But anyone who buys one will get the most satisfaction from smoking someone's doors off. The Tesla's message is that "green" technology can appeal to the id, not just the superego".

In December 2009, MotorTrend was the first to independently confirm the Roadster Sport'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.) Engineering Editor Kim Reynolds called the acceleration "breathtaking" and said the car confirms "Tesla as an actual car company. ...Tesla is the first maker to crack the EV legitimacy barrier in a century".

In November 2009, Automobile Magazine West Coast editor Jason Cammisa spent a week driving a production Tesla Roadster. Cammisa was immediately impressed with the acceleration, saying the car "explodes off the line, pulling like a small jet plane. ... It's like driving a Lamborghini with a big V-12 revved over 6000 rpm at all times, waiting to pounce—without the noise, vibration, or misdemeanor arrest for disturbing the peace". He also took the car to Infineon Raceway in Sonoma, California, and praised the car for its robustness, saying the Roadster:

"wins the Coolest Car I've Ever Driven award. Why? Despite the flat-out sprints, the drag racing, the donuts, the top-speed runs, and dicing through traffic like there's a jet pack strapped to the trunk, Pacific Gas and Electric—which generated power for the Tesla—released into the atmosphere the same amount of carbon dioxide as would a gasoline-powered car getting 99 mpg. And the Roadster didn't break. It didn't smoke, lock up, freeze, or experience flux-capacitor failure. Over the past ten decades, no company has been able to reinvent the car—not General Motors with the EV1, not Toyota with the Prius. And now, a bunch of dudes from Silicon Valley have created an electric car that really works—as both an environmental fix and a speed fix".

In 2009 the Tesla Roadster was one of the Scandinavian Sports Car of the Year participants. In a comparison made by Nordic car magazines Tekniikan Maailma (Finland), Teknikens Värld (Sweden) and Bil Magasinet (Denmark), critics praised the torque of the car and a track car structure, but also highlighted more negative aspects such as a short battery life; they were unable to drive a full track lap in dry track conditions.

In May 2009, Car and Driver technical editor Aaron Robinson wrote a review based on the first extended test-drive of a production Tesla Roadster. Robinson had the car for nearly a week at his home. He complained of "design anomalies, daily annoyances, absurd ergonomics, and ridiculous economics " and stated he never got to see if the car could go 240 miles on a single charge because the torturous seating forced him to stop driving the car. He also complained of Tesla increasing the car prices on those who had already made deposits and charging extra for previously free necessary components.

In February 2009, automotive critic Dan Neil of the Los Angeles Times called the production Tesla Roadster "a superb piece of machinery: stiff, well sorted, highly focused, dead-sexy and eerily quick". Neil said he had the car for 24 hours but "caned it like the Taliban caned Gillette salesmen and it never even blinked".

In February 2009, Road and Track tested another production vehicle and conducted the first independently verified metered testing of the Roadster. Engineering editor Dennis Simanitis said the testing confirmed what he called "extravagant claims", that the Roadster had a 4.0 s 0 to 60 mph (0 to 97 km/h) acceleration and a 200-mile (320 km) range. They said the Roadster felt like "an over-ballasted Lotus Elise", but the weight was well-distributed, so the car remained responsive. "Fit and finish of our Tesla were exemplary", which Road and Track thought fit the target market. Overall, they considered it a "delight" to drive. Testing a pre-production car in early 2008, Road and Track said "The Tesla feels composed and competent at speed with great turn-in and transitioning response", though they recommended against it as a "primary grocery-getter".

In January 2009, automotive critic Warren Brown of the Washington Post called the production Roadster "a head-turner, jaw-dropper. It is sexy as all get-out". He described the feeling behind the wheel as, "Wheeeeeee! Drive a Tesla, even if you have to fly to Tesla's Menlo Park, Calif., headquarters, to get your hands on one for a day. ... If this is the future of the automobile, I want it".

In a review of a Roadster prototype before the cars were in serial production, Motor Trend gave a generally favorable review in March 2008, stating that, it was "undeniably, unbelievably efficient" and would be "profoundly humbling to just about any rumbling Ferrari or Porsche that makes the mistake of pulling up next to a silent, 105 mpg Tesla Roadster at a stoplight".; however, they detected a "nasty drive-train buck" during the test drive of an early Roadster with the older, two-speed transmission.

In a July 8, 2007, review of a prototype Roadster, Jay Leno wrote, "If you like sports cars and you want to be green, this is the only way to go. The Tesla is a car that you can live with, drive and enjoy as a sports car. I had a brief drive in the car and it was quite impressive. This is an electric car that is fun to drive".

In a November 27, 2006, review of a prototype Roadster in Slate, Paul Boutin wrote, "A week ago, I went for a spin in the fastest, most fun car I've ever ridden in—and that includes the Aston Martin I tried to buy once. I was so excited, in fact, that I decided to take a few days to calm down before writing about it. Well, my waiting period is over, I'm thinking rationally, and I'm still unbelievably stoked about the Tesla".

Top Gear controversy

In the autumn of 2008, Top Gear's Jeremy Clarkson reviewed two production Roadsters with the v1.5 transmission and described the driving experience with the exclamations "God Almighty! Wave goodbye to the world of dial-up, and say hello to the world of broadband motoring!" and "This car is biblically quick!" when comparing the acceleration versus the car the Roadster was based on, a Lotus Elise. Clarkson also noted, however, that the handling of the car was not as sharp as that of the Elise: "through the corners things are less rosy". The Stig recorded a time of 1:27.2 on a moist track, faster than a Nissan 370Z on a dry track but slower than a Porsche 911 C2S also on a damp track, and also slower than the Lotus Exige, Exige S and Evora. The segment also claimed that the car's batteries would run flat after 55 miles (89 km) of heavy use on a track and showed the car being pushed off the track.

Tesla Motors' spokesperson responded with statements in blogs and to mainstream news organizations that the cars provided to Top Gear never had less than 20% charge and never experienced brake failure. In addition, neither car provided to Top Gear needed to be pushed off the track at any point. Finally, although Clarkson showed a limp windmill and complained that it would take countless hours to refuel the car using such a source of electricity, the car can be charged from a 240 V 70A outlet in as little as 3.5 hours. After numerous blogs and several large news organizations began following the controversy, the BBC issued a statement saying "the tested Tesla was filmed being pushed into the shed in order to show what would happen if the Roadster had run out of charge. Top Gear stands by the findings in this film and is content that it offers a fair representation of the Tesla's performance on the day it was tested", without addressing the other alleged misrepresentations that Tesla highlighted to the media. After several weeks of increasing pressure and inquiries from the BBC, Clarkson wrote a blog entry for The Times, acknowledging that "Inevitably, the film we had shot was a bit of a mess. There was a handful of shots of a silver car. Some of a grey car". "But as a device for moving you and your things around, it is about as much use as a bag of muddy spinach". In the months that followed Clarkson's acknowledgment, the original episode—including the misstatements—reran on BBC America and elsewhere without any editing, though the BBC is still looking into Top Gear's journalism standards, according to British media reports.

On March 29, 2011, Tesla sued the programme over libel and malicious falsehood, while simultaneously launching the website TeslaVsTopGear.com. The current position of Tesla is found on their web page. In a blogpost, producer Andy Wilman has referred to Tesla's allegations as a "crusade" and argued the truth value of Tesla's statements. On October 19, 2011, the High Court in London rejected Tesla's libel claim. Tesla appealed High Court's decision to the Court of Appeals, where a 3-judge panel of Lords Justice upheld the lower court's decision, and ordered Tesla to pay the BBC's legal costs of £100,000.

Awards

• INDEX: Award 2007
• BusinessWeek: Best Product Design of 2007, Ecodesign
• Forbes: Best Cars 2006: New car that best lived up to the Hype
• Time: Best Inventions 2008 – Transportation Invention
• Time: Best Inventions 2006 – Transportation Invention
• Popular Mechanics: Breakthrough Awards 2006
• Global Green USA: Product/Industrial Design
• CarDomain: People's Choice: Most Exciting 2007 Car Launch
• 2009 Best Green Exotic, duPont REGISTRY

See also

• List of electric cars currently available
• List of modern production plug-in electric vehicles
• List of production battery electric vehicles
• Detroit Electric SP.01
• Revenge of the Electric Car

References

• white papers and presentation
• [1]

External links

• Tesla Motors website
• Tesla Motors Club website
• Tesla Motors' list of media articles written about their product
• Wired News: "Batteries Included": First public review of the car.
• Tesla Sport Roadster: Product Review by Wired
• Motor Trend: First Drive of 2008 Tesla Roadster
• Renew America Roadtrip: America's First Green, Charity Drive Cross-Country in an all-electric production sportscar website
• Tesla Owner First Drive in Chicago
• How It Works: The Tesla Roadster
• Electrification 2.0 Tesla Model S
• Tesla Roadster – Fastest Electric Vehicle via http://www.carfinance247.co.uk