The Universal Postal Service is considering the possibility of fixing wind deflectors on the tops of 500 of their? long-haul tractors. Three types of? deflectors, with the following? characteristics, are being considered ?(MARR = 12% per year):

If 3?% in drag reduction means 2?% in fuel savings per? mile, how many miles do the tractors have to be driven per year before the windshear deflector is favored over the other? deflectors? Over what range of miles driven per year is? air-vantage the best? choice? (Note: Fuel cost is expected to be $3.25 per? gallon, and average fuel consumption is 4 miles per gallon without the? deflectors.)

Determine the range over which each deflector is preferred.

Blowby S600 9% $6 10 years Windshear Air-vantage S700 15% $9 10 years Capital investment $1,100 18% $4 6 years Maintenance per year Jseful life