When it comes to buying a car, we are all presented with a very large amount of options. I believe it is fair to say that among all the available options one of the most significant features that we are looking for is the car’s fuel efficiency. It is for this same reason that some people have chosen to purchase what is known as a hybrid car, and only another few lucky ones become the owner or a fully electric car. I will like to spend some time discussing these modern vehicles that requires only a fraction of gasoline or even down to no gasoline at all. On one hand we have one of the world’s first plug-in hybrid vehicle,the Fisker Karma. On the other hand we have the Tesla car which is completely electrical, hence no gasoline is required to run the motor of the car.
“The Karma’s charging strategy includes an on-board generator hooked to a 260-horsepower, 2.0-liter, four-cylinder, turbocharged, direct injection Ecotec engine”[1]. Depending on the terrain, speed and driving style the Karma’s software, that manages the battery and engine, will alternate the electric power and the use to gasoline. The Karma’s battery pack will operate the vehicle for a range of about 50 miles; as the battery run down, the system will kick-in the engine to drive the generator and provide additional power to the electric motors.[1] Similarly, “the heart of the Tesla Roadster is its 3-phase, 4-pole electric inductor motor, which weighs just 70 pounds. Tesla’s claims and independent testing show that the Roadster can reach 60 mph in about four seconds and its speed will.”[2]
In order for you to have a better idea of what are the main characteristics of these vehicles I decided to include the main specs of them:
Tesla Roadster:[2]
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Acceleration: zero to 60 in about 4 seconds
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Dimensions: 155.4 inches long, 73.7 inches wide, 44.4 inches tall with a 92.6-inch wheelbase
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Weight: 2,500 pounds (subject to change due to safety regulations)
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Top Speed: Over 130 mph
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Range: 250 miles EPA highway
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Battery Life: Useful battery life in excess of 100,000 miles
Fisker Karma: in order to improve its performance; the Karma offers the driver two driving modes the Stealth Drive and the Sport Drive below are the specs of each mode[1]
Stealth Drive
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Quiet, economy mode
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Allows drivers to travel up to 50 miles (80.5 kilometers) on a full battery charge
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Zero emissions
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0 to 60 miles per hour (96.6 kilometers per hour) in 7.5 seconds
Sport Drive
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Driving range is estimated at 300 miles (482.8 kilometers)
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An average of about 100 miles per gallon (42.5 kilometers per liter)
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The gas engine powers the generator that charges the batteries which then power the electric motors.
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Some emissions, but less than a typical gasoline engine
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0 to 60 miles per hour (96.6 kilometers per hour) in 5.8 seconds
You may wonder what makes these vehicles so interesting; and personally I believe that their biggest benefit is their electric powered motor. One of the advantages of using an electric motor to power a car is that, maximum torque can be produced almost instantly, unlike gasoline engines that need to ramp-up to several thousands of revolutions per minute before producing their maximum torque [1]. In the case of the Karma, like other hybrids, it takes advantage of regenerative braking to help stop the car and take advantage of the kinetic energy potential of the car during a coast or break situation. Regenerative braking uses generators that receive power from the wheels when the car either coasts or brakes and use the wheels inertia to generate a small charge which is then fed to the batteries. [2].
The Karma also can get recharged through a traditional AC home electrical system of a 240-volt AC system . On the other hand the Tesla Roadster gets the only power source through the Supercharger . “The Supercharger is a proprietary direct current (DC) fast-charging station that provides almost 120 kW of power, giving the 85 kWh Model S an additional 150 miles (240 km) of range in about 20 minutes, or 200 miles (320 km) of range in about 30 minutes.”
Because these cars are using little to zero gasoline; their emission an impact to the environment is very little. I believe that if this kind of vehicles become more affordable; they can become the car of the future and reduce significantly all the pollution from gas emission of gasoline motors
Sources
[1] http://auto.howstuffworks.com/fuel-efficiency/hybrid-technology/fisker-karma.htm
[2] http://auto.howstuffworks.com/tesla-roadster1.htm
[3] http://en.wikipedia.org/wiki/Tesla_Motors