TESLA ROADSTER: THE NEW STANDARD OF ELECTRIC AUTOMOBILES

Cara Hutter
Tyler Starmack
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.
University of Pittsburgh April 2, 2013
Swanson School of Engineering
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