## Wednesday, September 3, 2014

### Household consumption of fuel Yukon/Avenger versus Pilot/Prius.

Question:   Consider two households each with one SUV and sedan.   The first household has a Honda Pilot and a Toyota Prius.   The second Household has the GMC Yukon and the Dodge Avenger.   Both households drive 30,000 miles per year.

Create a spreadsheet calculates household fuel efficiency and gas consumption for the two households under three sets of assumptions on the percent of miles driven in the SUV.   The three assumptions are SUV use 25%, 50%, and 75% of the time.

Analysis:  The spreadsheet for the calculation of household vehicle fuel efficiency and household gas consumption involves five steps.

Step one is calculate miles driven in the SUV and Sedan by multiplying total miles by relevant percentage.

Step two is to calculate gas consumed in gallons for each vehicle.  Gas consume in each vehicle is vehicle miles driven divided by vehicle fuel efficiency.

Step three is to add gas used by SUV to gas used by the Sedan to get total gas consumed by the household.

Step four is to obtain household vehicle fuel efficiency, which is the quotient of vehicle miles traveled (30,000) and gallons of gas consumed found in step three.

Step five is to get expenditures on gas by multiplying the gallons of gas consumed by the price of gas, which is assumed at \$4.00.

Below are the results for the 25% SUV and 75% Sedan scenario.

 SUV Honda Pilot Yukon SEDAN Toyota Prius Dodge Avenger Input Usage Assumptions: Total Miles Traveled 30000 30000 % of Miles Traveled In SUV 0.25 0.25 Fuel Efficiency Assumptions SUV Overall Fuel Efficiency 21 17 Sedan Overall Fuel Efficiency 42 24 Mileage SUV 7500 7500 Sedan 22500 22500 Gas Consumed SUV 357.1 441.2 SEDAN 535.7 937.5 Total 892.9 1378.7 Overall Fuel Efficiency 33.6 21.8 Fuel  Expenditures @ \$4.00 gas \$3,571.4 \$5,514.7

Below are the results for the 50% SUV and 50% Sedan Scenario.

 SUV Honda Pilot Yukon SEDAN Toyota Prius Dodge Avenger Input Usage Assumptions: Total Miles Traveled 30000 30000 % of Miles Traveled In SUV 0.5 0.5 Fuel Efficiency Assumptions SUV Overall Fuel Efficiency 21 17 Sedan Overall Fuel Efficiency 42 24 Mileage SUV 15000 15000 Sedan 15000 15000 Gas Consumed SUV 714.3 882.4 SEDAN 357.1 625.0 Total 1071.4 1507.4 Overall Fuel Efficiency 28.0 19.9 Fuel  Expenditures @ \$4.00 gas \$4,285.7 \$6,029.4

Below are the results for

 SUV Honda Pilot Yukon SEDAN Toyota Prius Dodge Avenger Input Usage Assumptions: Total Miles Traveled 30000 30000 % of Miles Traveled In SUV 0.75 0.75 Fuel Efficiency Assumptions SUV Overall Fuel Efficiency 21 17 Sedan Overall Fuel Efficiency 42 24 Mileage SUV 22500 22500 Sedan 7500 7500 Gas Consumed SUV 1071.4 1323.5 SEDAN 178.6 312.5 Total 1250.0 1636.0 Overall Fuel Efficiency 24.0 18.3 Fuel Expenditures @ \$4.00 gas \$5,000.0 \$6,544.1

Concluding Thoughts:  Household vehicle choice has a large impact on fuel consumption and the household budget.  The Pilot/Prius combination is substantially more fuel efficient than the Yukon/Avenger combo.

The next post will look at the environmental costs of the vehicle combination choice based on different assumptions on vehicle use.