Gasoline Consumption by Passenger Vehicles

Comprehension

If you have a vehicle, use information about your driving habits to answer the following questions. If you don't drive but someone in your family does, use that vehicle to answer the questions. If you and your family all use mass transit, see what energy-related information you can gather about any mass transit you use. At this point, open your favorite word processor and start a journal. Copy the questions below to your journal and answer them.

  1. How much gasoline does your vehicle burn each week?
  2. Compare your estimate to those of other members of your group. What factors explain some of the differences?
  3. How much gasoline does an “average” vehicle burn?
  4. How much gasoline is burned by the vehicles of all your classmates? What additional factors did you consider?
  5. What information would you need to know to estimate the total amount of gasoline burned by US passenger vehicles in one year?
  6. Do you think that this amount will increase, decrease or stay the same?

Acquisition

General Information
Some of the factors you might have mentioned that influence the amount of gasoline burned are: the number of vehicles on the road; the number of miles each vehicle is driven; and the fuel efficiency of an average vehicle (mpg). In this module we examine each factor separately and then combine them to create one function to describe the total amount of gasoline burned by passenger cars in the US. Be sure to save the results for each factor

  1. Number of Vehicles
  2. Average Annual Mileage per Vehicle
  3. Average Fuel Efficiency

Application

Total Gasoline Consumption:
Refer to your journal entries for hints on how to proceed. Use the functions you derived above to answer these questions.

    Numeric estimate
    1. Predict each quantity for 2001: the number of passenger vehicles, the average miles driven per vehicle, and average fuel efficiency. Clearly state the units for each
    2. Predict the amount of gasoline that will be used by all passenger cars in the year 2001.
    3. Write a “word equation” describing the computation you carried out in 2). This may give you ideas for the next question.

    Deriving a function
    1. Write a function to predict the number of gallons of gasoline that will be used by passenger vehicles in year t; call the function G (t)..
    2. Graph G (t).
    3. What trends do you see in the data?
    4. How much gasoline will be consumed in 2005?
    5. When will the gasoline consumption reach 250 billion gallons?


    Reflection

    1. Reflection on the computation
      a. What did you do to predict gasoline consumption for a particular year?
      b. What did you do to predict when gasoline consumption reached a particular level?
    2. Reflection on the function
      a. Do you think your estimate is good for the next 5 years? 10 year?
      b. For how many more years do you think each function you derived will give a good estimate?
      c. What do you think is a reasonable domain for your function?
    3. Reflection of the interpretations
      a. What events might change each of the factors?
      b. Currently SUVs and pickup trucks have lower fuel efficiency than passenger cars. What changes would there be in gasoline consumption if these vehicles efficiency improved to the same level as passenger cars? What information would you need to answer this question?