Tesla Roadster

Infobox Automobile


name = Tesla Roadster
manufacturer = Tesla Motors
production = 2008–present
class = Roadster
platform = Unique, developed from Lotus Elise
body_style = Roadster
engine = 3-phase, 4-pole AC induction motor
length = convert|3946|mm|in|abbr=on
width = convert|1873|mm|in|abbr=on
height = convert|1127|mm|in|abbr=on
related = Lotus Elise
similar = Wrightspeed X1
AC Propulsion tzero
Venturi Fétish
designer = Tesla Motors, with help from Lotus Engineering and others
transmission = Single speed BorgWarner fixed gear
fuel_capacity = 53 kW·h (Li-ion battery)
electric_range = convert|244|mi|abbr=on
wheelbase = convert|2352|mm|in|abbr=on
front_track = convert|1464|mm|in|abbr=on
rear_track = convert|1499|mm|in|abbr=on
top_speed = convert|125|mph|km/h|abbr=on, electronically limited
layout = Rear Mid-engine, Rear-wheel drive
parent_company =
assembly = Lotus factory in Hethel, England
predecessor =
successor =
ground_clearance =
designer =
aka = Code name: DarkStar cite web |url=http://www.teslamotors.com/blog1/?p=47 |title=Vintage Oil and Other Hare-Brained Ideas |publisher=Tesla Motors |author=Martin Eberhard, Tesla Motors CEO |authorlink=Martin Eberhard |date=2007-01-24 |accessdate=2007-05-21 ]

The Tesla Roadster is a fully electric sports car. It is the first car produced by electric car firm Tesla Motors.

The car can travel convert|244|mi|km|abbr=on on a single charge of its lithium-ion battery pack and accelerate from 0-convert|60|mph|km/h|abbr=on in 3.9 seconds.

The Roadster's efficiency, as of February 2008, is reported as 199 W·h/km (3.12 mi/kW·h), equivalent to mpg|105.cite news |last = Rogers |first = John |title = Tesla rolls out its long-awaited electric sports car |publisher = Associated Press |date =2008-05-02 |language = English |url=http://green.yahoo.com/news/ap/20080502/ap_on_hi_te/electric_car.html |accessdate = 2008-05-02 ] cite web | url=http://www.teslamotors.com/blog2/?p=55 | title=A Letter to Customers from Ze’ev Drori | author=Ze’ev Drori, Tesla Motors President and CEO | date=2007-12-27 | accessdate=2007-12-31| publisher=Tesla Motors]

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.cite press release
publisher=Tesla Motors
title="Tesla Motors Hosts World Debut Of Tesla Roadster Offering Performance, Style & Efficiency — With A Conscience"
url=http://www.teslamotors.com/media/press_room.php?id=42
date=2006-07-20
accessdate=2007-04-24]

The San Francisco International Auto Show, held on November 18–26, 2006, was the Tesla Roadster's first auto show.

Development

The Roadster was developed by Tesla Motors with design help from Lotus Cars in certain areas. Lotus supplied the basic chassis development technology from its Lotus Elise, with which the Tesla engineers designed a new chassis. Barney Hatt at Lotus' design studio developed the styling with input from Tesla. 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.

The AC motor and drivetrain technology are more advanced than versions used in the GM EV1 and AC Propulsion tzero. Tesla Motors 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 Motors then designed and built its own power electronics, motor, and other drivetrain components that incorporate this licensed technology from AC Propulsion. cite web|url=http://www.acpropulsion.com/technology/reductivecharging.htm|publisher=AC Propulsion|accessdate=2007-03-07|title="Reductive Charging, AC Propulsion's Reductive Charger Integrated Charging for the Electric Vehicle"] cite web
url = http://www.autobloggreen.com/2008/06/24/autobloggreen-qanda-tesla-motors-chairman-elon-musk-part-2-tran/
title="AutoblogGreen Q&A: Tesla Motors Chairman Elon Musk Part 2 - Transmission shifts"
date=2008-06-24
accessdate= 2008-06-24
author= [http://www.autobloggreen.com/bloggers/sam-abuelsamid Sam Abuelsamid]
format=html]

Several prototypes of the Tesla Roadster were produced from 2004 through 2007. Initial studies were done in two "mule" vehicles. Ten Engineering Prototypes (EP1 thru EP10) were then built and tested in late 2006 and early 2007 which led to many minor changes. Tesla then produced seventeen Validation Prototypes (VP1 thru [http://www.facebook.com/photo.php?pid=349510&id=18790602800 VP17] ) which were delivered beginning in March 2007. These final revisions were endurance and crash tested in preparation for series production.

In January 2008 the NHTSA announced that it would grant a waiver of the [http://www.nhtsa.dot.gov/cars/rules/rulings/index_airbag.html "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.cite paper
author= NHTSA
url=http://edocket.access.gpo.gov/2008/pdf/E8-1359.pdf
title=Docket No. NHTSA–2008–0013. Tesla Motors, Inc.; Grant of Application for a Temporary Exemption From Advanced Air Bag Requirements of Federal Motor Vehicle Safety Standard No. 208
vol=73
no=18
date=2008-01-28
publisher = U.S. GPO
format=PDF] cite web
url=http://www.wtopnews.com/?nid=111&sid=1334524
title=Tesla Sports Car Gets Air Bag Waiver
author=Ken Thomas
date=2008-01-28
accessdate=2008-02-10
publisher=Associated Press]

Production

The car is assembled at the Lotus factory in Hethel, England, with drivetrain components and body components supplied to the factory by Tesla.cite web|url=http://www.teslamotors.com/blog4/?p=50|title=Cut From a Different Cloth|date=2007-02-15|accessdate=2008-02-15|author=Barrie Dickinson, Tesla Motors Director of Body Engineering|publisher=Tesla Motors]

The Roadster shares less than 10% of its components with the Lotus Elise; shared components are confined to the windshield, air bags, tires, some dashboard parts, and suspension components. The parts supply chain extends around the world; Tesla Motor's plant in Taiwan manufactures the motors and the Energy Storage Systems (ESS) was initially manufactured in Thailand during development and then moved to San Carlos, California after production started. Chassis are manufactured in Norway. SOTIRA, in St. Meloir & Pouancé France, create the RTM carbon fiber body panels. The Roadster's brakes and airbags are made by Siemens in Germany and crash testing was conducted at Siemens as well.cite news
publisher=Vanity Fair
url=http://www.vanityfair.com/politics/features/2007/05/tesla200705?currentPage=1
title=Quiet Thunder
author=Michael Shnayerson
date=2007-05
accessdate=2007-04-24] cite web
url = http://www.autobloggreen.com/2007/03/12/autobloggreen-qanda-tesla-motors-ceo-martin-eberhard-pt-1/
title="AutoblogGreen Q&A: Tesla Motors CEO Martin Eberhard pt.1"
accessdate= 2007-03-15
author= [http://www.autobloggreen.com/bloggers/sam-abuelsamid Sam Abuelsamid]
format=html] cite news
url=http://www.forbes.com/technology/2007/03/18/tesla-electric-car-tech-cz_ec_0319valleyletter.html?partner=rss
title=Can Silicon Valley Reinvent The Car?
publisher=Forbes
author= [http://www.forbes.com/fdc/bios/new/elizabethcorcoran.html Elizabeth Corcoran]
date=2007-03-17
accessdate=2007-03-26] cite web
url=http://www.jaylenosgarage.com/video/video_player.shtml?vid=229378
title=Jay Leno's Garage 2008 Tesla Roadster
date=March 2008
accessdate=2008-05-11
note=At 6:45 remaining in the video, Elon Musk's states that "it's [the body] made by SOTIRA in France"] cite news
url=http://online.wsj.com/article/SB120761191252596525.html?mod=hps_us_whats_news
title=Detroit Sets Bold Goal: Exporting U.S. Cars
date=2008-04-08
author=JOHN D. STOLL, NORIHIKO SHIROUZU and NEAL E. BOUDETTE
accessdate=2008-06-10
publisher=The Wall Street Journal
quote="Tesla Motors, a Northern California start-up developing an electric car, recently decided to scrap plans to build its $20,000-plus batteries in Thailand. Instead, it will assemble the components in the U.S. because of currency values."]

Production delivery was originally planned for October 2007 and then delayed, in September 2007, until the first calendar quarter of 2008. Series production of the car began on March 17, 2008cite web
url=http://www.teslamotors.com/blog2/?p=57
title=We have begun regular production of the Tesla Roadster
publisher=Tesla Motors
date=March 17, 2008
accessdate=2008-03-20] after over two years of prototyping and testing. However, the first production Roadster, referred to as "P1", was delivered to Tesla Motors' Chairman Elon Musk on February 1, 2008. cite news
publisher = New York Times
title=All Amped Up
date=2007-04-20
url = http://wheels.blogs.nytimes.com/2007/04/20/all-amped-up/
author = [http://wheels.blogs.nytimes.com/author/lulrich/ Lawrence Ulrich]
accessdate = 2007-04-24] cite web
url=http://www.teslamotors.com/display_data/customerletter_092407.pdf
title=Tesla Roadster Club Member Letter September 25, 2007
author=Michael E. Marks, CEO, Tesla Motors
date=2007-09-25
accessdate=2007-09-28
publisher=Tesla Motors] cite web
url=http://www.teslamotors.com/media/press_room.php?id=803
title=Tesla Motors Completes all Regulatory Approvals and Sets Schedule to Begin Production
date=2008-01-23
publisher=Tesla Motors] cite web
url=http://www.teslamotors.com/blog3/?p=72
title="Re: P1 Arriving Now! :)"
author=Zak Edson, Tesla Motors Sr. Manager Member Services
date=2008-02-06]

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 nowrap|0–60 mph 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 continuous torque requirements of the electric motor. In December 2007, Tesla Motors announced plans to ship the initial Roadsters with the transmissions locked into second gear to provide nowrap|0–60 mph 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 from convert|245|mi|km down to convert|221|mi|km. The downward revision was attributed to an error in equipment calibration at the laboratory that conducted the original test.cite web
url=http://qik.com/video/22264
title=Ride in first production Tesla with Elon Musk
author=Robert Scoble
date=2008-02-19
accessdate=2008-02-26
quote=2:58 into video Elon Musk says "This particular car [P1] actually has two speeds"] cite web
url=http://www.teslamotorsclub.com/4465-post11.html
date=2007-12-12
accessdate=2008-02-12
author=Daryl Siry, Tesla Motors Vice President of Sales, Marketing, and Service
title=Re: My Town Hall Notes]

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 17th, 2008. [ [http://www.greentechmedia.com/articles/tesla-production-slower-than-expected-908.html Tesla Production Slower Than Expected] , Greentech Media, May 16, 2008]

Subsequently, six more cars have been produced, for a total of nine as of July 2008. [cite news
url=http://www.teslamotors.com/blog2/?p=62
title=Update on Production and Delivery of Cars to Customers
publisher=Tesla Motors
date=2008-07-12
accessdate=2008-07-13]

On September 10, 2008, it was reported that 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 is hoped to reach 20 per week by December 2008, and 40 per week by March 2009. [ [http://wot.motortrend.com/6294593/green/tesla-declares-transmission-problems-solved-finished-roadster-now-in-production/index.html Tesla declares transmission problems solved, finished Roadster now in production] , Motor Trend, September 10, 2008] However, over the next 20 days, only 3 more had been delivered to customers, bringing the total to 30 as of September 30, 2008. [ [http://media.www.themichiganjournal.com/media/storage/paper255/news/2008/09/30/GoingGreen/Tesla.Roadster.Takes.Green.Trend.For.Joy.Ride-3460575.shtml Tesla Roadster takes green trend for joy ride] , The Michigan Journal, September 30, 2008]

ales

Tesla's "Signature One Hundred" initial set of fully equipped cars sold out by late August 2006. Tesla Motors then began accepting reservation orders by September 2006 for their 2008 models with several payment options available to determine the 2008 delivery date of the vehicle. The second hundred had been reserved by October. As of January 15, 2008, all 650 Tesla Roadsters planned for model year 2008 had been reserved. As it was initially only available in the USA, where traffic stays to the right-hand side of the road (RHT), Roadsters are only available with the steering-wheel on the left-hand side (LHD).

Final pricing for the 2008 Tesla Roadster base model was US$98,000, plus a destination charge of $950. The majority of the first 200 Roadsters ordered by October 2006 came fully loaded with all optional equipment at a cost of about US$100,000.cite web
url=http://www.teslamotors.com/buy/buyPage1.php
title=Join Our Wait List
author=Tesla Motors
accessdate=2008-02-12]

The company plans to begin sales in Europe during the third quarter of 2008, initially limited to 250 cars, at just under €100,000 each. [ [http://www.ft.com/cms/s/0/721ce1de-0059-11dd-825a-000077b07658.html Tesla to sell electric cars in Europe] ] The cars will not initially go on sale in the United Kingdom, where traffic stays to the left-hand side of the road (LHT), as there are no plans to build a Roadsters with the steering-wheel on the right-hand side (RHD). For 2009 Tesla plans to deliver 1500 cars. [ [http://www.physorg.com/news128963669.html Tesla rolls out its long-awaited electric sports car] ] The price for the 2009 models has been increased to US$109,000; options ranging from colors to audio to heavy duty cables can add another $10,000cite web
url=http://www.teslamotors.com/buy/buyPage1.php
title=Join Our Wait List
author=Tesla Motors
accessdate=2008-05-10]

Outside the United States

The 2009 Signature Edition Tesla Roadster became available in Europe on August 21, 2008. Only 250 cars are available, at 99,000 Euro. Reservations for the 2010 Roadster are available for a 3,000 Euro refundable reservation fee. [cite news
url=http://www6.lexisnexis.com/publisher/EndUser?Action=UserDisplayFullDocument&orgId=101846&topicId=104970025&docId=l:840211257
title=The Green Mean Machine
date=2008-08-21
author=Mark Prigg
Publisher=The Evening Standard (London)
accessdate=2008-08-22] [ [http://www.teslamotors.com/buy/resyourcar.php Tesla Motors] ]

Service

The first Tesla Motors Los Angeles, CA service center was opened on May 1, 2008 at [http://maps.google.com/maps?q=11163+Santa+Monica+Blvd,+Los+Angeles,+CA+90025,+USA 11163 Santa Monica Blvd, Los Angeles, CA 90025, USA] .cite web
url=http://www.autobloggreen.com/2008/05/02/first-tesla-store-opens-in-santa-monica-now-we-just-need-some-c/
title=First Tesla store opens in Santa Monica, now we just need some cars
date=2008-05-02
author= [http://www.autobloggreen.com/bloggers/sam-abuelsamid Sam Abuelsamid] ]

Tesla Motors publicly opened their second showroom and service area in Menlo Park, CA on July 22, 2008. The Menlo Park location will also be the final assembly area for Tesla Roadsters.

Additional service centers for the Tesla Roadster are planned for the following United States metropolitan areas:

*New York, NY
*Miami, FL
*Chicago, IL
*Seattle, WA

Tesla Motors has stated that it will build additional service centers over the next few years to support sales of its next vehicle, the sports sedan currently codenamed the Tesla WhiteStar. "To do 10,000 units for WhiteStar, we need to be in a lot more places," said Darryl Siry, vice president of Marketing.

Planning is underway for an additional 15 service centers in United States major metropolitan locations.cite news
url=http://pogue.blogs.nytimes.com/2007/04/05/solving-the-car-propulsion-problem/
title=Solving the Car Propulsion Problem
publisher=New York Times
author=David Pogue
date=2007-04-05] Possible locations for sales and service locations in Europe were announced in a [http://www.teslamotors.com/blog2/?p=59 letter to customers] in May, 2008.

A Roadster purchased in the United States but more than 100 mi. from the nearest service center was originally announced as requiring an additional US$8,000 out-of-service-area fee; this fee was removed at the start of production and replaced with a policy that customers will be responsible for transporting their Roadster to a service center.cite web
url=http://www.teslamotors.com/blog2/?p=59
title=Program Update
date=2008-05-15
author=Tesla Motors
publisher=Tesla Motors] No "independent" mechanics are authorized or certified to perform maintenance on the drive train or electrical systems of the Roadster.cite web
author =
title = Tesla Motors FAQs
version =
publisher = Tesla Motors
date=2006-12-20
url = http://www.teslamotors.com/learn_more/faqs.php?flat=1#faq-q-item23
format = HTML
accessdate = 2006-12-20]

There is minimal maintenance required for an electric vehicle. There are no oil changes, and brake maintenance is minor due to regenerative braking. Transmission, brake and cooling system fluids will need to be changed in a manner similar to gasoline-powered cars.

Specifications

Motor

The roadster is powered by a 3-phase, 4-pole electric motor, producing a maximum net power of 248 hp (185 kW). The motor is designed for rotational speeds of up to 14,000rpm, and delivers an efficiency of typically 90%, or 80% at peak power.

Transmission

* BorgWarner single speed fixed gear

Tesla Motors builds all Roadsters with a single speed fixed gear with electrically-actuated parking lock mechanism and mechanical lubrication pump.

The company previously worked with several companies, including XTrac and Magna International, to find the right 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 (0-60mph in 5.7 seconds instead of the announced 4.0 seconds). Tesla will subsequently upgrade those transmissions under warranty when the final BorgWarner transmission is available. cite web | url = http://www.autoblog.com/2007/12/19/tesla-clarifies-report-of-temporary-transmissions/ |date=2007-12-19 |title=Tesla clarifies report of "temporary transmissions" | first = John | last = Neff ] 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 nowrap|0–60 mph in under 4 seconds and an improved motor limit of 14,000 rpm to retain the convert|125|mi/h|km/h|abbr=on top speed. [ [http://www.teslamotors.com/display_data/town_hall_01312008.mp3 "Town Hall Meeting" with owners on January 30, 2008] ] In addition, the upgraded system improved the maximum torque from convert|200|ft.lbf|N.m|abbr=on to convert|280|ft.lbf|N.m|abbr=on.

Performance

*Acceleration time: nowrap|0–60 mph nowrap|(0–97 km/h) in 3.9 seconds. Some prototypes and initial production 2008 Roadsters were limited to 5.7 second nowrap|0–60 mph acceleration.
*Top speed: electronically limited at 125 mph (201 km/h)
*Range: convert|244|mi|km|abbr=on on the EPA combined cyclecite web
url=http://www.teslamotors.com/media/press_room.php?id=968
date=2008-09-09
publisher=Tesla Motors
author=Tesla Motors
title=Tesla Motors Selects BorgWarner for Production of New Gearbox for Tesla Roadster]
*Weight and distribution: about 2,700 lb (1,220 kg), centered in front of the rear axle
*Rear wheel drive

Battery system

* Cell type: lithium ion, 18650 form-factor (18 mm diameter by 65 mm length). Most laptop computer batteries already use this type of lithium-ion cell.
* Cell count: 6,831 cells arranged into 11 modules connected in series; each module contains 9 "bricks" connected in series; each "brick" contains 69 cells connected in parallel (11S 9S 69P).cite web
url=http://www.teslamotors.com/display_data/pressguild.swf
title=The Future of Cars is Electric
author=Martin Eberhard, Tesla Motors CEO
authorlink=Martin Eberhard
publisher=Tesla Motors
date=2007-08-07
quote=Video available from [http://video.google.com/videoplay?docid=-6124789175148491596 Google Video] . Slide 90 shows that "The ESS consists of 6831 individual cells that are electrically connected into parallel groups of 69 cells." (11S 9S 69P)] cite web
url=http://www.teslamotors.com/display_data/Tesla_rebuttal_ZEV_expert_panel.pdf
title=Response to the CARB ZEV Expert Panel Position on Lithium-Ion Full-Performance Battery Electric Vehicles
author=Andrew Simpson, Telsa Motors
date=March 23, 2008
publisher=Tesla Motors
format=PDF
language=EN] cite web
url=http://www.elecdesign.com/Articles/Index.cfm?AD=1&AD=1&AD=1&ArticleID=14108
title=Roadster Gets 250 Miles Per Charge
author= [http://www.elecdesign.com/Authors/AuthorID/1585/1585.html Sam Davis]
magazine=Electronic Design
issue=Best Electronic Design 2006
month=12
year=2006
quote="Battery packs consist of 11 identical groups of 621 lithium-ion cells (called sheets) connected in series and parallel. Each cell is 18 mm in diameter and 650 mm long with a nominal 3.6 V and a 2.2 A·h rating."]
* Full-charge time: 3½ hours.
* Estimated life: Recommend replacing at 100,000 miles (160,000 km) or 5 years, whichever comes first.
* Replacement cost: Estimated $20,000 circa 2008 [http://www.teslamotorsclub.com/tesla-motors/218-buying-replacement-ess.html#post1063]
* Electric energy: about 53 kW·h
* Total mass: between 900 and 1000 lb (400-450 kg)

The pack is designed to prevent catastrophic cell failures from propagating to adjacent cells, even when the cooling system is off. Tesla Motors had planned to sell the battery system to "TH!NK" and possibly others through its Tesla Energy Group division. That plan was put on hold by interim CEO Michael Marks in September 2007.cite news
author = [mailto:[e-mail]?subject=San%20Jose%20Mercury%20News:%20Tesla%20Motors%20to%20sell%20batteries%20in%20%26#36;43%20million%20deal%20with%20Think Matt Nauman]
title = Tesla Motors to sell batteries in $43 million deal with Think
url = http://www.mercurynews.com/business/ci_5956932
format = html
publisher = San Jose Mecury News
date=2007-05-22
accessdate = 2007-06-19
language = EN
quote = ] cite web
url=http://www.autobloggreen.com/2006/11/29/tesla-motors-ready-to-license-batter-tech-to-other-companies/
title="EDTA Conference: Tesla Motors ready to license battery tech to other companies"
accessdate=2007-03-11
author= [http://www.autoblog.com/bloggers/sebastian-blanco/ Sebastian Blanco]
format=html] cite web
url=http://www.news.com/8301-10784_3-9798162-7.html
title=Tesla delays its battery business, but test drives begin
date=2007-10-16
accessdate=2008-02-09
author= [http://www.news.com/8300-10784_3-7.html?authorId=129&tag=author Michael Kanellos]
publisher=News.com]

Energy efficiency

In June 2006, Tesla Motors reported the Roadster's battery-to-wheel efficiency as 110 W·h/km (5.65 mi/kW·h) 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 (4.85 mi/kW·h). cite web | url = http://ev.inel.gov/pdf/fsev/eva/genmot.pdf |title="EVAmerica Baseline Performance Testing for 1997 General Motors EV1 with PbA Batteries" |accessdate=2007-03-05 |author=Idaho National Laboratory |authorlink=Idaho National Laboratory | format = pdf | quote = Footnote 8 in Tesla Motor's white paper refers to this INL study for the equivalent efficiency number from GM EV1 testing but does not specify the driving cycle. ] cite paper | author = Martin Eberhard, Marc Tarpenning | title = The 21st century Electric Car | publisher = Tesla Motors | date = 2006-10-06 | url = http://www.teslamotors.com/display_data.php?data_name=21stCentElectricCar | format = PDF | accessdate = 2007-02-23 ]

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 (4.66 mi/kW·h) battery-to-wheel and 155 W·h/km (4.00 mi/kW·h) plug-to-wheel. cite paper | title = Musk Testimony | author = Elon Musk | publisher = United States Senate Committee on Energy & Natural Resources |date=2007-03-07 | url = http://energy.senate.gov/public/_files/MuskTestimony.doc | format = Microsoft Word | accessdate = 2007-03-14] cite press release |url=http://www.teslamotors.com/media/press_room.php?id=53&js_enabled=0 |title=Tesla Motors Corporate Backgrounder |accessdate=2006-12-05 |publisher=Tesla Motors |format=html |quote=...the Tesla Roadster is capable of 135 mpg equivalent...] cite web |url=http://www.edmunds.com/insideline/do/News/articleId=116204 |title=Tesla Roadster: Lotus Helps Create Sporty 135 MPG Electric Car |accessdate=2006-12-05 |author=Edmunds.com Inside Line |authorlink=Edmunds.com |date=2006-07-21 |format=html |language=English |quote=...achieves the equivalent of 135 mpg.] cite news |last = Neil |first = Dan |title = A roadster that's electric |publisher = Marketplace Public Radio |date =2006-07-20 |language = English | url = http://marketplace.publicradio.org/shows/2006/07/20/PM200607208.html |accessdate = 2006-09-18 ]

In August 2007, Tesla Motors' dynamometer testing of a Validation Prototype on the EPA combined cycle yielded a range of convert|221|mi|km|abbr=on using 149 W·h/km (4.17 mi/kW·h) battery-to-wheel and 209 Wh/km (2.98 mi/kW·h) plug-to-wheel. cite web |url=http://www.teslamotors.com/blog4/?p=60 |title="Where the Rubber Meets the Road" |author=Andrew Simpson, Tesla Motors Vehicle Systems Engineer |date=2007-09-24 |accessdate=2008-02-22 |quote=Mr. Simpson confirmed via email that "We do not quote station-to-wheel efficiency, but we do quote plug-to-wheel efficiency which includes all energy use downstream of the charging plug. For the most-recent convert|221|mi|km|abbr=on range test, our plug-to-wheel efficiency was 336 Wh/mi." ]

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 (354 km) and a plug-to-wheel efficiency of 256 mpg equivalent or 199 W·h/km (3.12 mi/kW·h).cite web
url=http://www.teslamotors.com
title=Tesla Motors
accessdate=2008-06-25
quote=256 mpg equivalent*, 220 miles per charge*, less than 2¢ per mile*...* Range is based on our most recent testing with a Validation Prototype car at an EPA-certified location in February 2008. EPA range is subject to change pending future testing. Actual range will vary with driving style and conditions. Conversion from electric consumption to gallons of gasoline equivalent is calculated using the Department of Energy equivalence factor documented in the Code of Federal Regulations, Section 10, Part 474. ]

The Roadster's motor efficiency, battery-to-wheel, is 90% on average and 80% at peak power (this does not include the efficiency of the electrical generating source, only how efficiently the Roadster uses the energy).cite web
url=http://www.teslamotors.com/learn_more/faqs.php?flat=1#faq-q-item13
title="Electric Vehicle (EV) Questions"
accessdate=2008-07-14] For comparison, internal combustion engines have a tank-to-wheel efficiency of about 20%. cite web | url = http://www.fueleconomy.gov/feg/atv.shtml | title = Advanced Technologies and Energy Efficiency | accessdate = 2008-02-10 | author = US EPA ]

Petroleum-equivalent efficiency

Because the Roadster does not actually use gasoline, petroleum-equivalent efficiency (mpg, l/100 km) can be calculated in several ways:

A number comparable to the typical Monroney sticker's "pump-to-wheel" fuel efficiency can be calculated based on the DOE's energy content for a U.S. gallon of gasoline of 33705 W·h/gal (also called the Lower Heating Value (LHV) of gasoline):

: $frac\{33705,frac\{mathrm\{W\; cdot\; h\{mathrm\{gal\}\; \{149,frac\{mathrm\{W\; cdot\; h\{mathrm\{km\; imes\; frac\{1.6,\; mathrm\{km\{mathrm\{mi\}\; imes\; 75.2\%\; =\; 105\; ,mathrm\{mpg\}\; =\; 2.24\; frac\{mathrm\{L\{100,\; mathrm\{km$

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 conservation and scarcity of fuels in the USA. cite paper
author = U.S. Department of Energy (DOE)
title = Federal Register Vol. 64 No. 113
publisher = U.S. GPO
date=2000-07-12
url = http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=2000_register&docid=00-14446-filed.pdf
format = PDF
accessdate = 2006-09-22 ] This combination yields a factor of 82,049 W·h/gal in the above equation and a regulatory fuel efficiency of mpg|256.

Recharging with electricity from the USA grid, the factor changes to 12,307 W·h/ U.S. gal to remove the "fuel content factor" = ¹/_0.15 and the above equation yields a full-cycle energy-equivalency of mpg|38.4. 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 [http://www.fueleconomy.gov/feg/compx2008f.jsp?year=2008&make=Toyota&model=Prius&hiddenField=Findacar mpg|46] , for example, converts to a full-cycle energy-equivalent of mpg|38.2.

Recharging with electricity generated by newer, 58% efficiency CCGT power plants,cite news
url=http://www.fossil.energy.gov/news/techlines/2003/tl_baglanbay.html
title = Advanced Natural Gas Turbine Hailed as Top Power Project of 2003
publisher = DOE
date=2003-12-30
language = English
accessdate = 2007-03-14 ] changes the factor to 21,763 Wh/gal in the above equation and yields a fuel efficiency of mpg|68.

Recharging with non-fossil fuel electricity sources such as hydroelectric, solar power, wind or nuclear, the equivalent efficiency can be remarkably higher as fossil fuel is not used in refueling.cite web
url=http://www.fueleconomy.gov/feg/evtech.shtml
title=http://www.fueleconomy.gov/feg/evtech.shtml
accessdate=May 28, 2008]

Monetary cost offers another way to find an equivalent fuel efficiency. Tesla Motors reports an energy cost of approximately US$0.01/mile using PG&E's [http://www.pge.com/mybusiness/environment/pge/cleanair/electricdrivevehicles/charging/index.shtml E-9 night-time incentive charging] , or about US$0.03/mile using the retail price of US$0.12/kW·h. Comparison with a gasoline price of US$3.50/ U.S. gallon, for instance, results in an equivalent of mpg|350 using E-9 or mpg|117 using retail pricing.

Reviews

In a November 27 2006 review of the Tesla 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."cite web
url=http://www.slate.com/id/2154425/
title="It's Electric!The Tesla Roadster—a hotshot sports car that runs on batteries."
author=Paul Boutin
publisher=www.Slate.com
date=2006-11-27]

In a July 8, 2007 review of the Tesla 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."citation
url=http://driving.timesonline.co.uk/tol/life_and_style/driving/new_car_reviews/article2036260.ece?OTC-HPtoppuff&ATTR=tesla
title=Tesla Roadster - The most fun you can have without fuel
author=Jay Leno
publisher=The Sunday Times
date=2007-07-08]

In a March 2008 article "Car and Driver" had this to say about the Tesla Roadster: "Highs: Intoxicating midrange powertrain response, user-friendly operation, realistic range, Lows: expensive for performance, iffy shifter, unknown reliability and life cycle, The Verdict: if we wanted an electric car, we’d be happy to live with this one".cite news
url=http://www.caranddriver.com/reviews/hot_lists/car_shopping/green_machines/2008_tesla_roadster_road_test
title=2008 Tesla Roadster - Road Test
publisher=Car and Driver
date=2008-06-17]

"Motor Trend" gave a generally favorable review, 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 drivetrain buck" during the test drive.cite news
url=http://www.motortrend.com/roadtests/alternative/112_0803_2008_tesla_roadster/index.html
title=First Drive: 2008 Tesla Roadster
publisher=Motor Trend
accessdate=2008-03-21]

"AutoWeek" reported that while "the roadster has had a few transmission troubles [...] Tesla Roadster buyers will enjoy their energy-efficient mounts. We know we did."cite news
url=http://www.autoweek.com/apps/pbcs.dll/article?AID=/20080124/FREE/398811820/1024/FREE
title=Tesla Roadster: Don't worry about the future of transportation being fun
publisher=AutoWeek
date=2008-01-24
accessdate=2008-03-21]

"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".cite news
url=http://www.roadandtrack.com/article.asp?section_id=2&article_id=6393
title=First Drive: 2008 Tesla Roadster
publisher=Road and Track
date=March 2008
accessdate=2008-03-21]

Awards

* INDEX - INDEX Award 2007cite web
url=http://www.indexaward.dk/2007/default.asp?id=709&Article=847&Folder=847
title=INDEX Award 2007]
* BusinessWeek - Best Product Design of 2007, Ecodesigncite web
url=http://www.businessweek.com/magazine/content/07_31/b4044401.htm
title=Best Product Design of 2007, Ecodesign]
* Forbes - Best Cars 2006: New car that best lived up to the Hypecite web
url=http://www.forbes.com/lifestyle/2006/12/08/best-cars-2006-forbeslife-cx_dl_1211bestcars.html
title=Best Cars 2006: New car that best lived up to the Hype]
* Time Magazine - Best Inventions 2006 - Transportation Invention [ [http://www.time.com/time/2006/techguide/bestinventions/ TIME Best Inventions 2006 ] ]
* Popular Mechanics - Breakthrough Awards 2006 [cite web | last = Ward | first = Logan | title = BREAKTHROUGH AWARDS 2006: Innovators Martin Eberhard and Team | publisher = Popular Mechanics | date = November 2006 | url = http://www.popularmechanics.com/science/research/4212847.html | accessdate = 2008-01-23]
* Global Green USA - Product/Industrial Design [cite press release | title = Tesla Motors Receives 'Environmental Leadership' Award from Global Green USA | publisher = Tesla Motors | date = 2006-10-17 | url = http://www.teslamotors.com/media/press_room.php?id=190 | accessdate = 2008-01-23] [cite web | title = Awards | publisher = Global Green USA | url = http://www.globalgreen.org/awards/secure_sustainable.html | accessdate = 2008-01-23]
* CarDomain - People's Choice: Most Exciting 2007 Car Launch [ [http://blog.cardomain.com/blog/2006/11/peoples_choice.html CarDomain Car Blog: People's Choice! ] ]
*2009 Best Green Exotic, "duPont REGISTRY"cite web |url=http://www.autoblog.com/2008/10/09/dupont-registrys-11-best-of-cars-set-horsepower-price-record/ |title=duPont Registry's 11 "Best of" cars set horsepower, price records |accessdate=2008-03-20 |last=Ramsey |first=Jonathon |date=2008-10-09 |format=HTML |work=Autoblog |publisher=Weblogs, Inc. |language=English]

See also

* List of production battery electric vehicles

Footnotes

References

*
*
* [http://www.teslamotors.com/learn_more/white_papers.php white papers] and [http://www.teslamotors.com/display_data/bconverted.swf presentation]

External links

* [http://teslamotors.com/ Tesla Motors home page]
* [http://www.teslamotors.com/media/media_coverage.php?js_enabled=1 Tesla Motors' list of media articles written about their product]
* [http://www.wired.com/wired/archive/14.08/tesla.html Wired News: "Batteries Included"] - First public review of the car.
* [http://www.motortrend.com/roadtests/alternative/112_0803_2008_tesla_roadster/index.html Motor Trend- First Drive of 2008 Tesla Roadster]
* [http://www.futurecars.com/reviews/tesla-roadster.html Tesla Review by FutureCars.com]