To get gallons per mile you need to average your duty cycle per mile, and multiply by 3.7 and that answer by 6. This will give you CC's per Mile. Now convert CC's to gallons (1 gallon = 3785.4 CC's) So at 100% duty cycle you would use .59 gallon per mile at an unknown efficiency. At 50% duty you would use .29 gallon per mile. At 25% duty you would use .14 gallon per mile giving you 7.1 miles per gallon.
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