TESLA ROADSTER: THE NEW STANDARD OF ELECTRIC AUTOMOBILES

Session A9 

Paper 3096 

TESLA ROADSTER: THE NEW STANDARD OF ELECTRIC AUTOMOBILES 

Cara Hutter (cdh32@pitt.edu, Bursic 2:00), Tyler Starmack (tas143@pitt.edu, Bursic 2:00) 

Abstract-In recent years, reducing energy consumption and 

emissions has been a priority for those with economic and 

environmental concerns. Electric automobiles provide an 

improvement upon existing automobiles by completely 

eliminating the need for oil and gasoline. Some automobile 

companies, such as Chevrolet and Nissan, have developed 

their own models of electric cars; however, Tesla Motors 

was created primarily for the design, development, and 

production of electric cars. One such car, the Tesla 

Roadster, uses rechargeable Lithium-ion batteries, which 

provide a very high energy density at a relatively low cost. 

This paper will explain how electricity is a suitable, 

more efficient, and economical alternative to gasoline by 

comparing the Tesla Roadster to a similar gasoline-powered 

car. It will also discuss, in detail, the mechanics behind the 

three main systems of the Tesla Roadster. In addition, the 

paper will describe the performance of the Roadster, as it 

pertains to the efficiency and emissions produced by the car. 

Within the discussions of efficiency, emissions, and 

performance of the Roadster, the sustainability of the vehicle 

will also be analyzed. 

Hesitation to purchase an electric car is primarily based 

on the fact that most have insufficient power and a limited 

range. However, Tesla Motors shows that the correct use of 

technology allows the Roadster to contradict popular belief. 

Therefore, the Tesla Roadster will likely become the 

standard for electric cars in the near future. 

Key Words-Efficiency, electric automobiles, internal 

combustion engine, Lithium-ion battery, Tesla Motors, Tesla 

Roadster 

INTRODUCTION: THE NEED FOR A NEW 

STANDARD 

Often, when one thinks of an electrically powered 

vehicle, something akin to a golf cart is pictured-not usually 

powerful or reliable. This may change, however, in the years 

to come. Since its establishment in 2003, the all-electric 

automotive company, Tesla Motors, has been testing, 

developing, and designing cars that will run on only 

electricity, not gasoline. Their goal is to change the 

automotive industry by developing sustainable technology 

for cars that will eliminate harmful emissions and the need 

for gasoline (and thus, foreign oil) [1]. 

Their most groundbreaking design, the Tesla Roadster, 

includes both of these elements as well as having an 

attractive design and comfortable interior. The technology 

involved, while quite complex, is actually simpler and far 

superior in efficiency to a standard car with an internal 

combustion engine. Because of its superiority to cars on the 

road presently, it is likely that the technology in the Roadster 

will become the new standard in all automobiles in the 

coming years. 

A BRIEF HISTORY OF TELSA MOTORS 

Tesla Motors was founded in 2003 in Silicon Valley, 

California for the purpose of developing and manufacturing 

cars that run only on electricity. The roots of this company 

can be traced back to Stanford’s Solar Car project, in which 

a team of students led by J.B. Straubel created and raced a 

car that used only solar power. Although their car finished 

fifteenth in the race, the student engineers realized that it 

was possible to run the car without the use of solar energy if 

they used a larger Lithium-ion battery. This idea inspired 

J.B. Straubel, with the help of PayPal founder Elon Musk, to 

establish Tesla Motors [1]. 

Although the company had high ambitions, it faced 

extreme challenges that it had to overcome in order to stay in 

business. As Georgios Sarakakis, Noah Lassar, and Christian 

Frederickson say in their paper concerning the development 

of the Tesla Roadster, “It [Tesla Motors] was a small startup 

company in an industry of big, established brands 

requiring large capital investment” [2]. Because of this, 

Tesla Motors had to work especially hard to keep themselves 

in business by developing quality products that would be 

desirable to consumers. This in itself was a challenge 

because the technology for electric automobiles was largely 

unproven and therefore not trusted by average consumers. 

In order to overcome this challenge, Tesla Motors 

engaged in extensive data collection of the Roadster and 

continues to work to improve designs even after they appear 

on the market. They also own all of their stores so that 

accurate records of service events are kept. In this way, 

Tesla Motors is able to collect more data on aspects of the 

vehicle that are malfunctioning in order to continue to 

improve its design as well as gaining the trust of the 

customer by providing quality service. 

In addition to the challenge of catering to the wary 

consumer, Tesla Motors also had to face the challenge of 

finding quality materials for which to construct the Roadster. 

Since electric vehicles eliminate the use of gasoline, the 

entire mechanical layout of the car is different. There is no 

need for an engine in such a car, only electrical components. 

Because these components are entirely different than 

anything that is normally used, Tesla Motors had to build a 

new supply chain in order to acquire the materials needed. 

This was especially difficult because the Roadster was being 

developed in the late 2000s during the recession that hit the 

United States. Engineers from Tesla said, “Often, suppliers 

were either unwilling to work with a small electric vehicle 

University of Pittsburgh April 2, 2013 

Swanson School of Engineering 

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Cara Hutter 

Tyler Starmack 

start-up, or their capabilities were not up to the quality, 

reliability, and performance goals of the Roadster” [2]. Tesla 

Motors has since been able to create an effective supply 

chain that allows them to manufacture their vehicles. 

The fact that Tesla Motors has worked (and continues to 

work) so hard to overcome the challenges of being a small 

start-up company developing new technology shows that 

they are extremely committed to their goal of creating 

efficient, reliable, and affordable electric cars as well as 

possibly providing other car companies with this technology. 

An article from Stanford magazine about the beginnings and 

future plans of Tesla Motors says, “They’re out to inspire 

change, not dominate the market,” and J.B. Straubel himself 

says, “The long term goal is to transform the whole 

transportation industry, not just make a better sports car” [1]. 

The Roadster is indeed an amazing sports car, but it is only 

the beginning for Tesla Motors in their quest to develop 

affordable electric vehicles that the average consumer is able 

to purchase. 

Lithium-ion batteries are presently quite popular in 

technology (used in cell phones, laptops, etc.). They are very 

recyclable- 96 percent of their materials can be recovered, 

and they are often reused before they are recycled because 

they can still carry a substantial charge, thus making them a 

great sustainable energy source. They are also quite 

lightweight and have a high energy density. This means that 

a battery of this type can store a large amount of energy 

relative to its size, which makes it perfect for use in an 

electric vehicle. If an electric car were to not use Lithiumion 

batteries, it would instead use nickel metal hydride 

batteries, which are much heavier and have a low energy 

density. Such a car would require more than a thousand 

kilograms of them [4]. 

FIGURE 2 

ELECTRIC INNOVATIONS: THE 

TECHNOLOGY BEHIND THE TESLA 

ROADSTER 

Before comparisons between the Tesla Roadster and 

gasoline-powered cars are made, it is important to 

understand the technology behind the Roadster. Because it is 

an all-electric car, the components that cause it to run are 

completely different than a car with a standard internal 

combustion engine (ICE). The following sections will 

describe the three main systems that make the Roadster 

work: the Electronic Storage System (ESS), the Power 

Electronics Module (PEM), and the electric motor. These 

systems can be seen in the diagram below (Figure 1). 

FIGURE 1 

DIAMGRAM OF SYSTEMS [3] 

The Electronic Storage System (Battery Pack) 

Because the Roadster does not use gasoline, it must get 

power from another source. In this car, power comes entirely 

from a battery pack called the Electronic Storage System 

ELECTRONIC STORAGE SYSTEM [3] 

Since Lithium-ion batteries have a high energy density, it 

is very important that the battery pack be safeguarded 

against overheating. In the Roadster, such precautions are 

taken to ensure overheating does not occur among other 

issues that arise with the use of electricity (i.e. short 

circuits). This is done mainly through the layout of the 

battery pack and the addition of devices within the pack. 

Each of the Lithium-ion cells is 18 millimeters in 

diameter and 65 millimeters in length (slightly larger than a 

AA battery) and 69 of them are wired together in parallel to 

make ‘bricks’. Nine of these ‘bricks’ are wired together in 

series to make a sheet (Figure 3), and 11 sheets are inserted 

into the case (Figure 4) [5]. The advantage of having many 

sheets of batteries is that it greatly increases the surface to 

volume ratio. Engineers at Tesla say, “Surface area is 

essential to cooling batteries since the surface is where heat 

is removed; more is better” [4]. Because the cells are wired 

into sheets, there is space between these sheets for a 

temperature control device. In addition, there is a device 

called a Current Interrupt Device (CID), which responds in 

the event that a cell has excessive internal pressure which is 

a result of high temperature. If this event occurs, the CID 

will break, causing no current to flow into the cell, thus 

isolating it from the others. If these cells were not isolated 

when such an event occurred, it could set off a chain 

reaction that would affect the other cells and cause more 

severe damages. 

(ESS), which is made up of Lithium-ion cells (Figure 2). 



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FIGURE 3 

another system to control how much energy is being drawn 

from it, which will be discussed in the next section. 

The Power Electronics Module 

SHEET OF 621 BATTERIES [3] 

FIGURE 4 

ELEVEN SHEETS OF BATTERIES ARE PLACED IN 

THE CASE [3] 

In addition to controlling the temperature of the battery 

pack, there are also devices in place to prevent electrical 

malfunctions such as short circuits. Each cell has two fuses, 

one on the cathode (positive end) and one on the anode 

(negative end). These fuses are designed to blow (break) if 

the electrical current passing through them is above a certain 

amount. A sudden increase in current is usually the result of 

a short circuit. When either one of the fuses break, the cell is 

completely separated electrically from the rest of the cells, 

eliminating the chance of it harming the others. Each of the 

sheets also has a fuse to prevent short circuits across the 

whole sheet [4]. 

Also within the ESS are numerous microprocessors and 

sensors that, under normal circumstances communicate with 

the vehicle to monitor the state of the ESS (such as 

temperature and amount of charge). Under more adverse 

circumstances however, these systems have the ability to 

signal to the high voltage contractors to disconnect the 

battery pack (which has a high voltage that can be 

dangerous) from the car [4]. This prevents the high voltage 

from harming the driver. 

It is very fitting that the ESS would have all of these 

safety features since it is one of the most important systems 

of the Roadster. The Lithium-ion batteries are the reason that 

it has enough power to travel more than 200 miles on a 

single charge as well as accelerate from 0 to 60 miles per 

hour (mph) in less than four seconds [4]. This system cannot 

exist on its own in the Roadster, however. There must be 

As stated above, the ESS must have some other system 

to control how much and what kind of energy must be drawn 

from it. This system is called the Power Electronics Module 

(PEM) and is a vital part of the Roadster’s technology. Tesla 

Motors says that it, “functions as a bridge for energy 

between the charge port, battery, and the motor” [6]. This 

means that all of the energy that the Roadster uses must 

travel through this system at some point. 

The PEM in its most basic use controls current. The ESS 

stores power in what is called direct current (DC), but the 

current that comes from charging sources (i.e. power outlet) 

and the current that the motor uses is alternating current 

(AC). Current that is referred to as direct only flows in one 

direction, whereas alternating current reverses direction 

periodically. One of the PEM’s main functions then, is to 

convert current from AC to DC or vice versa [6]. 

In order for the PEM to function effectively, there are 

three main systems that work together: the power stages, the 

controller, and the line filter. The power stages, also known 

as the Megapoles, are arrays of switches that control whether 

the battery is connected to the charge port or the motor. 

Within the Megapoles there are six switches grouped in pairs 

called half-bridges, each of which form a phase in the motor 

(this will be discussed in greater detail in the next section). 

Each of the six switches is composed of 14 Insulated Gate 

Bipolar Transistors (IGBT) (Figure 5). These IGBTs control 

the amount and type of current that is passed through the 

PEM. The IGBTs create alternating current by turning off 

and on rapidly [6]. 

FIGURE 5 

IGBTs [6] 

The system that manages these switches is the controller, 

which has the ability to turn the switches on and off up to 

32,000 times per second. The controller contains two 

processors called the digital signal processor (DSP) and the 

secondary safety processor. The DSP is mainly responsible 

for interpreting requests from the Vehicle Management 

System, controlling torque, and changing behaviors of the 

system. The secondary safety processor, on the other hand, 



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functions as a current monitor. If the current going to the 

motor is inconsistent with the acceleration pedal, it will stop 

the system [6]. This prevents the Roadster from accelerating 

more than the driver intends. 

The last system in the PEM is the line filter. The line 

filter is a series of inductors (devices that store energy in 

magnetic fields) called chokes that are placed between the 

charge port and the IGBTs. Their purpose is to filter out 

electrical noise which is a result of the IGBTs are turning off 

and on at a rapid rate while the Roadster is charging. This 

noise, if allowed to conduct back through the power lines, 

would cause interference in other electronic devices such as 

radios and cell phones [6]. 

The PEM is indeed a complex system that is incredibly 

important to the Roadster. It, in combination with the ESS, 

provides the necessary power to run the electric motor, 

which will be discussed, in detail, in the next section. 

The Electric Motor 

The ESS and PEM are vital to the functioning of the 

Roadster-they would mean nothing if the electric motor did 

not exist. In order for the car to drive, the motor is essential 

because it is connected to the back axel and therefore the 

wheels. The type of motor that the Roadster uses is called a 

three-phase AC induction motor, and is one of the most 

common types of electric motors (Figure 6). 

FIGURE 6 

ELECTRIC MOTOR [7] 

The motor consists of two main parts: the rotor and the 

stator (Figure 7). The rotor consists of a steel shaft with 

copper bars running through it. As the rotor turns, the wheels 

do as well, moving the car. The stator is stationary and 

encases the rotor, but does not touch it. 900 amperes (amps) 

of current are delivered to the stator through copper wires 

(used for their low resistance, and therefore can endure more 

current) that are wound through a stack of steel plates. There 

are three sets of these wires, each corresponding to the three 

phases of the motor [7]. 

FIGURE 7 

CROSS SECTION OF ELECTRIC MOTOR. ROTOR: 

INNER BLUE CIRCLE, STATOR: OUTER RING [8] 

As the alternating current from the PEM flows through 

the copper wires in the stator, a magnetic field is produced 

that, like the current, alternates between a North and South 

Pole. The three phases of the motor occur because of the 

three sets of alternating currents in the three sets of wires. 

The magnetic fields resulting from each set of wires are 

slightly out of time with each other. This creates a ripple of 

magnetic field travelling around the stator. Tesla Motors 

describes this by way of analogy, “The magnetic field 

appears to move in a circular path around the stator- similar 

to the way spectators in a sports stadium create the illusion 

of a ‘wave’ by alternating between standing or sitting in 

concert with other fans” [7]. 

The magnetic field from the stator then induces a current 

in the copper bars within the rotor, which then creates an 

opposite magnetic field around the rotor, due to Lenz’s Law. 

This law states, “An induced current has a direction such 

that the magnetic field due to the current opposes the change 

in magnetic flux that induces the current” [9]. This means 

that the rotor will have a magnetic field that is opposite of 

the stator, and because the magnetic field of the stator is 

constantly moving around in a circle, the rotor will spin to 

follow it. This, in turn, will provide the torque that is 

necessary to spin the wheels. The rotor is also positioned in 

such a way that its magnetic field is always “behind” the 

stator’s. This ensures that the rotor keeps spinning. This also 

means that the farther behind the rotor is from the stator, the 

more torque is being produced (when accelerating) [7]. 

Torque, then, is always being produced as long as the 

rotor is spinning. This means that there is no need for this 

type of automobile to have a transmission with gears since it 

produces effective torque at a wide range of rpms (rotations 

per minute). This simplifies the running process of the 

Roadster to an extreme degree since there are little to no 

timing issues possible (unlike a car with an ICE). There is 

also no reverse “gear” in the Roadster. All that needs to be 

done in order to put the car in reverse is to switch two of the 

phases of the motor so the magnetic field runs in the 

opposite direction. This completely eliminates the need for a 

transmission, and thus increases the Roadster’s efficiency 

and contributes to its sustainability, which will be discussed 

in the next section [7]. 



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SUSTAINABILITY OF THE ROADSTER 

The sustainability of the Tesla Roadster comes solely 

from the types of technology included in its make-up. The 

Lithium-ion batteries, for example, contribute heavily to its 

environmental impact as well as its energy sustainability. 

They prove to be quite recyclable since 96 percent of each 

cell can be recovered. This is done simply by bringing them 

to a plant where they are shredded and sorted through to 

recover the metal components. In most cases, however, they 

are reused before they are recycled. A Lithium-ion battery 

typically still has about 80 percent of its charge left after it 

can no longer be used by a car, so it is then used for other 

purposes, such as in solar panels and windmills, before it is 

recycled [10]. It is in this way that the batteries contribute to 

the overall sustainability aspect of the Roadster. They reduce 

the amount of waste by being reused and recycled, rather 

than being thrown away. Also, the fact that they are more 

powerful than other batteries for their size also means that 

less have to be made. 

But Lithium-ion batteries are not the only things that 

make the Roadster more sustainable. The electric motor 

contributes a very large degree to sustainability through its 

efficiency. The efficiency of the motor is mostly due to the 

fact that it does not need to convert energy or motion very 

drastically. For example, in an ICE car, in order to achieve 

rotational motion in the wheels, it must be converted from 

the linear motion of the pistons. In an internal combustion 

engine, the pistons move up and down in sequence in order 

to turn the driveshaft. The driveshaft then connects to the 

differential to which an axel (front or rear) is attached to. 

This then causes the wheels to turn. This is very unlike the 

electric motor, which is connected directly to an axel and 

turns the wheels. There is no need for so many conversions 

in motion. In fact, the electric motor used in the Tesla 

Roadster achieves 88 percent efficiency- much unlike an 

ICE which has about 30 percent efficiency [7]. 

It is largely because of the motor and batteries, then, that 

the Roadster can claim to be part of the sustainability 

movement. These two pieces of technology cause the car to 

use almost all of the energy supplied to it, rather than much 

of it being wasted, as well as have little environmental 

impact. 

Sustainability is based on the principle that everything 

needed for survival depends on the environment [11]. 

Therefore, the technology used in everyday life should be 

made to reduce harmful emissions that are released into the 

atmosphere. Automobiles certainly fit into the category of 

this form of technology. Currently, the conventional, 

gasoline-powered vehicle emits tremendous amounts of 

harmful carbon dioxide into the atmosphere, which prevents 

it from being classified as sustainable. The Tesla Roadster 

provides an improvement upon current automobiles by 

increasing efficiency and reducing emissions, thus making it 

a more sustainable form of transportation. This increased 

sustainability provides the foundation of the value behind 

the Tesla Roadster. 

TESLA ROADSTER: A COMPARISON TO 

GASOLINE-POWERED AUTOMOBILES 

To show the value behind an electric automobile, 

specifically the Tesla Roadster, it is necessary to compare 

the Roadster to similar gasoline-powered vehicles. This 

section will compare three main differences between the two 

types of vehicles: efficiency, emissions, and performance. 

The sustainability of the Roadster will also be analyzed 

during each comparison. 

Efficiency 

In order to provide an accurate representation of the 

efficiency of a vehicle, the overall, well-to-wheel energy 

efficiency must be computed. Well-to-wheel efficiency is 

the best overall representation of the efficiency of a vehicle 

because it combines both the efficiency of the car itself and 

fuel production from the well to the wheel of the car. The 

computation of efficiency of a car is done in four steps. The 

first step is to consider the energy content of the source fuel 

as it comes from the ground (i.e. coal, crude oil, or natural 

gas). Next, the energy content of the fuel is tracked as it is 

converted to its final product, either gasoline or electricity. 

Then, the energy needed to transport the fuel to the car is 

subtracted from the total amount. Finally, the fuel efficiency 

of the car is used to complete well-to-wheel efficiency [12]. 

As a reference, energy content of fuels will be presented in 

terms of mega-joules per kilogram (MJ/kg), and overall 

efficiency is expressed in terms of kilometers driven per 

mega-joule (km/MJ) of fuel consumed [12]. A higher wellto-wheel 

efficiency describes the more efficient vehicle. A 

comparison between the Tesla Roadster and the similarly 

built, gasoline-powered Honda Civic VX will show the 

difference in total efficiency. The 1993 Honda Civic VX 

will be analyzed first. 

Gasoline’s energy content is roughly 47 MJ/kg, and the 

production and transportation of gasoline is 81.7% efficient 

on average. This means that 18.3% of gasoline’s energy 

content is lost during production and transportation. The VX 

has an Environmental Protection Agency (EPA)-rated 51 

miles-per-gallon (mpg) of gasoline combined city and 

highway driving. Therefore, its efficiency is 0.52 km/MJ. A 

typical car gets half the mpg of the VX, making it the most 

efficient gasoline-powered vehicle made to date [12]. 

A combined cycle, natural gas-fired electric generator is 

considered to be the most efficient way to generate 

electricity [12]. The best of these generators is 60% efficient, 

meaning that 40% of the natural gas’s energy content is lost 

in generation. However, the recovery, processing, and 

transportation have a combined average efficiency of 87.5%, 

giving a total production efficiency of 52.5%. In the Tesla 



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Roadster, the Lithium-ion batteries are about 86% efficient, 

and the car’s efficiency is 2.53 km/MJ. Taking into account 

the production efficiency, the well-to-wheel efficiency is 

1.14 km/MJ [12]. 

Figure 8 presents the well-to-wheel efficiency of six 

different vehicles. Each vehicle is run by a different form of 

technology. The Honda CNG is a natural gas engine, the 

Honda FCX is run by a hydrogen fuel cell, the VW Jetta 

Diesel uses a diesel engine, and the Toyota Prius is a hybrid, 

which combines both gasoline and electricity. It is clear that 

the Tesla Roadster has a much greater well-to-wheel 

efficiency than any other type of automobile. In fact, it is 

more than double its nearest competitor, the Toyota Prius. 

Since gasoline, oil, and natural gas are all nonrenewable 

resources, meaning they will become depleted in the future, 

limiting their use is essential to ensure sustainability. The 

Roadster, and electric cars in general, only use a fraction of 

these resources compared to gasoline-powered vehicles. 

Additionally, the resources that are used in making 

electricity are used more efficiently by the Roadster than any 

other vehicle with fewer emitted emissions, which will be 

analyzed in the next section. 

FIGURE 8 

dioxide emissions can be calculated. Therefore, the overall 

emission of the VX is 141.7 grams/kilometer (g/km), and the 

emission of the Roadster is 46.1 g/km [12]. 

In this case, a smaller well-to-wheel carbon dioxide 

emission is more desirable. Figure 9 shows compares the 

overall emissions of each of the same vehicles described 

before. It is again quite clear that the Tesla Roadster 

outmatches its competitors. With a total emission that is 3.07 

times less than the Honda Civic VX and 2.83 times less than 

the hybrid Toyota Prius, the Roadster shows that electric 

automobiles can help to significantly reduce the amount of 

carbon dioxide that is released into the atmosphere. 

During the process of burning fuel, many different types 

of emissions are produced, including carbon dioxide. Most 

of these greenhouse gases are released into the atmosphere, 

which can cause significant damage, specifically the ozone 

layer. Lowering automobile emissions is one way to ensure 

the protection of the environment and atmosphere. The 

limited carbon dioxide emissions of the Roadster provide 

another example of the sustainability of the vehicle. 

Most vehicles that are considered high performance, for 

example, the Porsche Turbo or Ferrari Maranello, have 

incredibly high carbon dioxide emissions. Even though the 

Tesla Roadster is a high performance car, which will be 

shown in the next section, the carbon dioxide emission is 

significantly less than any other high performance vehicle. 

FIGURE 9 

WELL-TO-WHEEL EFFICIENCY [12] 

Emissions 

Using the energy efficiency of a vehicle and the carbon 

content of the source fuel, it is possible to calculate and 

compare the well-to-wheel emissions of any form of vehicle. 

However, the main focus of the emissions comparison will 

again be between the Tesla Roadster and the Honda Civic 

VX.. During the process of combustion, when the fuel is 

burned, all of the carbon in a vehicle’s fuel source becomes 

carbon dioxide, which can be harmful to the atmosphere 

[12]. 

Crude oil, the fuel source of the Honda Civic VX, has a 

carbon content of 19.9 grams per mega-joule (g/MJ), while 

natural gas has a carbon content of only 14.4 g/MJ. Every 

gram of carbon is converted to 3.67 grams of carbon dioxide 

because of the two oxygen molecules added to each carbon 

molecule. So, the content of carbon dioxide in crude oil is 73 

g/MJ, and natural gas has a carbon dioxide content of 52.8 

g/MJ. By dividing carbon dioxide content by each vehicle’s 

respective overall efficiency, the well-to-wheel carbon 

WELL-TO-WHEEL CARBON DIOXIDE EMISSIONS 

[12] 

Overall Performance 

The main drawback to owning a car like the Tesla 

Roadster is the purchase price of the vehicle. With a base 

price of about $109,000 [2], the Roadster is several times 

more expensive than a conventional gasoline-powered 

automobile. This high price is primarily due to that fact that 

the number of electric automobiles being sold is greatly less 

than their gasoline counterpart. Until the volume of sales of 

electric cars is comparable to gasoline-powered cars, it will 

be necessary to compare other aspects of the two vehicles. 

Efficiency and emissions point greatly in favor of electric 



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automobiles, but what really sets the Roadster above and 

beyond its competition is performance. 

Performance, which is measured by a combination of 

torque, or horsepower, and efficiency, gives the Tesla 

Roadster an edge over gasoline-powered vehicles. An 

internal combustion engine produces a very small amount of 

torque at a low number of revolutions-per-minute (rpm) and 

can only supply reasonable horsepower in a small range of 

rpm [12]. However, as shown in Figure 10, the Roadster 

delivers high torque from very low rpm to around 6,000 

rpm. It can also continue to produce torque well beyond the 

point of any combustion engine, although the amount of 

torque begins to slowly decline after 6,000 rpm [7]. 

Although the base price of the Roadster may appear to 

point away from the vehicle’s sustainability, the high price is 

only temporary. Once the new technology of the Roadster 

becomes more commonly used and the volume of 

production of electric automobile increases, the price will 

continually drop [12]. The combined efficiency, emitted 

emissions, performance, and innovation of Tesla Motors will 

allow the Roadster to be a sustainable vehicle in the future. 

FIGURE 11 

FIGURE 10 

TORQUE PRODUCTION OF AN ELECTRIC MOTOR 

AND GASOLINE ENGINE [7] 

Efficiency plays a large role in the production of 

horsepower. With a gasoline engine, performance comes 

with large consequences. Due to the complexity of the 

internal combustion engine, a large amount of energy is 

wasted. At best, only about 30% of the energy stored in 

gasoline can be converted into torque. In order to overcome 

the internal losses of the engine, the vehicle must idle at 

around 1,000 rpm [7]. Additionally, the acceleration of an 

automobile is based on the horsepower of the engine. If 

rapid acceleration is desired, a high-horsepower engine is 

required, which will lead to very poor gas mileage [12]. 

However, an electric motor is able to convert electricity into 

mechanical power, while acting as a generator, turning 

mechanical power back into electricity with an overall 

efficiency of 88% [7]. Incredible efficiency and torque 

production allows the Tesla Roadster to accelerate as well 

as, if not better than, the best sports cars of today [Figure 

11]. As shown in Figures 9-11, the Roadster is able to 

perform at a very high level, while being six times more 

efficient and producing one-tenth the emissions of other high 

performance vehicles, including the Porsche Turbo, Ferrari 

Maranello, and the Chevrolet Corvette [11]. 

ACCELERATION COMPARISON [12] 

TESLA MOTORS: SETTING THE 

STANDARD 

When the Tesla Roadster took to the streets in 2008, 

skepticism and major challenges plagued Tesla Motors. The 

unproven technology from a small start-up company added 

to the hesitation to purchase the Roadster. Public perception 

of electric cars only increased the skepticism to purchase an 

all-electric performance sports car. Tesla Motors sought not 

only to fight these challenges, but to change the public 

perception of electric vehicles. In order to succeed in the 

market, it was necessary for Tesla Motors to use a rapid 

production and improvement of their products [2]. 

Tesla Motors demonstrated its commitment to 

improvement through the Roadster. In its first three years on 

the market, Tesla Motors upgraded the design of the 

Roadster four times, which is a record for a new car 

company [2]. Each new design brought improvements to 

nearly every major aspect of the car. Range, performance, 

and reliability have increased [Figure 12], and the interior 

and exterior styling also improved with each design change 

[2]. The improvements made to the Roadster are a direct 

result of the innovative processes used by Tesla Motors. 



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Cara Hutter 


FIGURE 12 

VEHICLE FAILURES PER 100 THOUSAND MILES 

(2008-2011) [2] 

Innovation is a key requirement in any company, 

especially those which have just entered the market, and 

Tesla has proven to be a leader in the advancement of 

electric automobiles. Tesla Motors uses a mobile service 

team, called the Tesla Rangers, to perform most service calls 

at the customer’s house [2]. The Rangers offer a very unique 

and convenient method of servicing a car. Instead of leaving 

a vehicle at a shop and waiting until the appointment is over, 

customers can simply call the Rangers and never have to 

leave their home. Tesla also demonstrates that an electric 

car, such as the Roadster, is much different than its gasolinepowered 

counterpart by showing that vehicle improvements 

do not always require the need of a mechanic. Most 

improvements are simply updates of the firmware (software) 

and not changes to the hardware [2]. Firmware updates can 

even be done remotely with permission and assistance from 

the customer [2]. 

The innovation of Tesla Motors has helped the 

company to succeed despite the challenges it faced. The 

Tesla Roadster also has shown that electric cars are not just a 

futuristic dream. Lithium-ion batteries, an Electronic Storage 

System, the Power Electronics Module, and the electric 

motor have already been developed enough to allow the 

Roadster to travel up to 245 miles per charge. Efficiency, 

emissions, and performance of the Tesla Roadster are overall 

much better than a conventional vehicle. Each of these 

aspects contributes towards making the Roadster a more 

sustainable vehicle. In fact, in an interview with MIT 

Professor Donald Sadoway, he said, “The only reason that 

(electric) car isn't everywhere: it couldn't go more than 70 

miles on a charge. But you make it 270, game over. 

Anybody who drives it will never go back to internal 

combustion” [12]. With a 245 mile range, it seems clear that 

Tesla Motors achieved its goal of changing the public 

perception, and they may have even set a new standard in 

the electric automobile industry. 

REFERENCES 

[1] A. Marsh. (2008). “The Electric Company”. Stanford 

Magazine. (Online Article). 

http://alumni.stanford.edu/get/page/magazine/article/?article 

_id=31675. 

[2] G. Sarakakis, N. Lassar, C. Fredrickson. (2011). 

“Reliability insights from 15 million electric miles”. Tesla 

Motors. (Online Article). 

http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6 

175469. 

[3] (2011) “Tesla Motors Club”. Tesla Motors. (Online 

Article). 

http://www.teslamotorsclub.com/showthread.php/3810- 

Roadster-battery-(ESS) 

[4] G. Berdichevsky, K. Kelty, JB Straubel, E. Toomre. 

(2007). “The Tesla Roadster Battery System”. Tesla Motors. 

(Online Article). 

http://webarchive.teslamotors.com/display_data/TeslaRoadst 

erBatterySystem.pdf. 

[5] (2013) “Battery”. Tesla Motors. (Online Article). 

http://www.teslamotors.com/roadster/technology/battery 

[6] (2013) “Power Control”. Tesla Motors. (Online Article). 

http://www.teslamotors.com/roadster/technology/powerelectronics-module 

[7] (2013) “Motor”. Tesla Motors. (Online Article). 

http://www.teslamotors.com/roadster/technology/motor 

[8] (2013) “Basic Polyphase Devices” (picture). Industrial 

Electronics Information for Manufacturing Applications. 

http://www.industrial-electronics.com/polyphasedevices/Basic-Polyphase-devices.html 

[9] D. Halliday, R. Resnick, J. Walker. (2012). 

Fundamentals of Physics: Extended, Ninth Edition. John 

Wiley & Sons, Inc. (Print book). pp. 794. 

[10] K. Hall-Geisler (2011). “Can Electric Car Batteries Be 

Recycled?”. How Stuff Works. (Online Article). 

http://www.howstuffworks.com/can-electric-car-batteriesbe-recycled.htm 

[11] (2013). “Sustainability”. Environmental Protection 

Agency. (Online Article). 

http://www.epa.gov/sustainability/basicinfo.htm. 

[12] M. Eberhard, M. Tarpenning. (2006). “The 21 st Century 

Electric Car”. Tesla Motors. (Online Article). 

http://www.stanford.edu/group/greendorm/participate/cee12 

4/TeslaReading.pdf 

ADDITIONAL SOURCES 

E. Grabianowski. (2011). “How the Tesla Roadster Works”. 

How Stuff Works. (Online article). 

http://auto.howstuffworks.com/tesla-roadster.htm. 

ACKNOLEDGEMENTS 

We would like to thank the writing staff for their assistance 

in class and helpful resources. Their explanations provided a 

clear and understandable overview of the task of this paper. 

We would also like to thank Ross Hutter for his assistance in 

selecting an interesting and relevant topic. 



8

TESLA ROADSTER: THE NEW STANDARD OF ELECTRIC AUTOMOBILES

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