Elon Musk's Tesla Roadster, a 2008-era car scheduled to be launched towards Mars

The Tesla Roadster is a battery electric vehicle (BEV) sports car that was produced by the electric car firm Tesla Motors (now Tesla, Inc.) in California from 2008 to 2012. The Roadster was the first highway legal serial production all-electric car to use lithium-ion battery cells and the first production all-electric car to travel more than 320 kilometres (200 mi) per charge.[7]

Tesla sold about 2,450 Roadsters in over 30 countries,[8][9][10] and most of the last Roadsters were sold in Europe and Asia during the fourth quarter of 2012.[11] Tesla produced right-hand-drive Roadsters from early 2010.[12] The Roadster qualified for government incentives in several nations.[13][14]

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 40 km/h (25 mph) .[15][16] 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.[17]

According to the U.S. EPA, the Roadster can travel 393 kilometres (244 mi) on a single charge[18] of its lithium-ion battery pack, and can accelerate from 0 to 97 km/h (0 to 60 mph) in 3.7 or 3.9 seconds depending on the model. Its top speed is 201 km/h (125 mph). 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.[19]

In November 2017, Tesla demonstrated their planned Tesla Roadster (2020) model, with advertised 0 to 97 km/h (0 to 60 mph) acceleration of 1.9 seconds.

Motor[edit]

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 185 kW (248 hp).[103] Its maximum torque of 200 lb⋅ft (270 N⋅m) is immediately available and remains constant from 0 to 6,000 rpm;[104] nearly instantaneous torque is a characteristic 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.[105][106]

The Sport Model introduced during the Jan 2009 Detroit Auto Show includes a motor with a higher density, hand-wound stator that produces a maximum of 288 hp (215 kW).[107] Both motors are designed for rotational speeds of up to 14,000 rpm, and the regular motor delivers a typical efficiency of 88%[19] or 90%; 80% at peak power. It weighs less than 70 pounds (32 kg).[108]

Transmission[edit]
Starting in September 2008 Tesla 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.[18]

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 97 km/h (0 to 60 mph) 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.[73][75][109] 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 201 km/h (125 mph) top speed.[110] The upgraded system also improved the maximum torque from 270 to 380 N⋅m (200 to 280 lb⋅ft) and improves the Roadster's quarter mile times.[citation needed]

Gear selector[edit]
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[edit]
The Roadster's 0 to 97 km/h (0 to 60 mph) acceleration time is 3.9 seconds for the Standard model and 3.7 seconds for the 2010 V2.5 Sport, which MotorTrend confirmed in the first independent, instrumented testing the Sport. The magazine also recorded a 0-to-1⁄4-mile (0.00 to 0.40 km) time of 12.6 seconds at 165.1 km/h (102.6 mph).[111] Tesla said the top speed is electronically limited to 201 km/h (125 mph). Tesla claims it has a weight of 1,305 kg (2,877 lb), a drag coefficient of Cd=0.35–0.36[112] and a rolling resistance of Crr=0.011.[42]

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 97 km/h (0 to 60 mph) in 3.7 seconds.[113] 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.[114] The EPA combined range (specifying distance traveled between charges) measured in February 2008 for early production Roadsters was 372 km (231 mi) city, 360 km (224 mi) highway, and 365 km (227 mi) combined (city/highway).[115] In August 2008, additional testing with the newer Powertrain 1.5 resulted in an EPA combined range of 393 km (244 mi).[18] The vehicle set a new distance record when it completed the 388-kilometre (241 mi) Rallye Monte Carlo d'Energies Alternatives with 58 km (36 mi) left on the charge.[116] A Roadster drove around the world (although flying as cargo over oceans) in 2012,[117] and repeated it in 80 days with other electric cars in 2016.[118]

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.[119]

Battery system[edit]

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 refers to the Roadster's battery pack as the Energy Storage System or ESS. The 450 kg (992 lb) 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),[120] while researchers at DTU/INESC Porto state lithium manganese oxide (LMO).[121] LiCo has higher reaction energy during thermal runaway than LMO.[122]

The pack is designed to prevent catastrophic cell failures from propagating to adjacent cells (thermal runaway), even when the cooling system is off.[123] 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.[60][124][125][126] The cooling and battery management system keeps the temperatures and voltages within specific limits.[127]

Charging unit
A full recharge to 53 kWh (190 MJ) requires about 3½ hours using the High Power Connector which supplies 70 amp, 240 volt electricity.[128][129]

Tesla said in February 2009 that the ESS had expected life span of 7 years/160,000 km (100,000 mi), and began selling pre-purchase battery replacements for about one third of the battery's price today, with the replacement to be delivered after seven years. Tesla says the ESS retains 70% capacity after 5 years and 80,000 km (50,000 mi) of driving, assuming 16,000 km (10,000 mi) driven each year. A July 2013 study found that after 160,000 km (100,000 mi), Roadster batteries still had 80%–85% capacity and the only significant factor is mileage (not temperature).[130]

Tesla 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.[131][132][133] TH!NK now obtains their Lithium-Ion batteries from Enerdel.

Recharging[edit]
The Roadster uses a proprietary charging connector, although Tesla sells a mobile adapter that enables recharging with an SAE J1772-2009 connector.[6] The vehicle can be recharged using:[134]

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.[135]
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 90 km (56 mi)-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 8.0 km (5 mi)-of-range for each hour charging; a complete recharge from empty would require 48 hours.[136]

Technical data[edit]
Tesla Roadster[137] Tesla Roadster ("P1")[138] 1.5 Standard Tesla Roadster 2.0[139] Tesla Roadster 2.5 base Tesla Roadster 2.5 Sport[140] Tesla Roadster R80 (3.0) upgrade
Introduced 2006 2007 2009 2010 2010 2014
Transmission 2 forward speeds + reverse (by reversing the motor)
1st gear: 4.20:1
2nd gear: 2.17:1Reverse by reversing the motor (speed electronically limited)
Final drive: 3.41:1
Single speed BorgWarner fixed gear (8.27:1 ratio)
Power 185 kW (248 hp) 185 kW (248 hp) 185 kW (248 hp) 215 kW (288 hp) 215 kW (288 hp) 215 kW (288 hp)
Torque 240 N⋅m (180 lb⋅ft) 370 N⋅m (273 lb⋅ft) 370 N⋅m (273 lb⋅ft) 370 N⋅m (273 lb⋅ft) 400 N⋅m (295 lb⋅ft) 400 N⋅m (295 lb⋅ft)
Battery 53kWh 53kWh 53kWh 53kWh 53kWh 80kWh
Range 320 to 400 km (200 to 250 mi) 372 km (231 mi) 393 km (244 mi) 393 km (244 mi) 393 km (244 mi) 640 km (400 mi)
Aerodynamics 0.36 0.36 0.36 0.36 0.36 0.31
0–100 km/h
(62 mph)

around four seconds
5.7 seconds (limited due to durability)

4.0 sec 3.9 sec 3.9 sec 3.7 sec 3.7 sec
Curb weight (kg) / (lb)
All fluids, 50% fuel

1,305 kg (2,877 lb) 1,305 kg (2,877 lb) 1,237 kg (2,727 lb) 1,237 kg (2,727 lb) 1,237 kg (2,727 lb)
Top speed over 130 mph 201 km/h (125 mph) 201 km/h (125 mph) 201 km/h (125 mph) 201 km/h (125 mph) 201 km/h (125 mph)