Fuel usage in automobiles refers to the fuel efficiency relationship between distance traveled by an automobile and the amount of fuel consumed. The miles per gallon gasoline equivalent is based on the energy content of gasoline. The energy obtainable from burning one US gallon is 115,000 BTU. Thus one mile per gallon gasoline equivalent is equal to 115,000 BTU per mile. For alternative fuels, energy required to manufacture the fuel may also be considered. For electrical power, the energy of any fuels used to generate the electricity and the transmission efficiency must be considered.
Gallons Per Hour Consumption Calculation  GPH
Table of Contents:
Formula
Aviation Gasoline weight per gallon (gw) =6.00
Jet A weight per gallon (dw) =6.84
Total Capacity (AvGas) Fuel Load Weight=(Fuel weight)* (gw)
GPH=start fuelend fuel
To convert the mile per gallon rating into other units of distance per unit energy used, the mile per gallon value can be multiplied by one of the following factors to obtain other units:
1 MPGe 
= 8.55 miles/ million BTU 
≈ 0.0292 miles/kW·h 

≈ 0.0182 /kW·h 

≈ 0.005 km/MJ 
In 1994 the U.S. National Institute of Standards and Technology (NIST) introduced gasoline gallon equivalent (GGE) as a metric for fuel economy for natural gas vehicles. NIST defined a gasoline gallon equivalent (GGE) as 5.660 pounds of natural gas, and gasoline liter equivalent (GLE) as 0.678 kilograms of natural gas
NOTE:
Be sure to take into consideration winds aloft, restricted zones, climb time and fuel for a margin of safety when calculating requirements. Be sure to check the current NOAA aviation weather for departure, along the flight plan and at the destination airport before departure. Free online Mechanical engineering Calculators.
Example:
Calculate the Gallon per hour fuel consumption by the given details.
Enter Fuel Capacity in Gallons for All Tanks = 15
Enter Trip Time Elapsed In Hours = 25
Enter Starting Fuel In Gallons In All Tanks = 10
Enter Ending Fuel In Gallons In All Tanks = 5
Solution:
Apply Formula:
Aviation Gasoline weight per gallon (gw) =6.00
Jet A weight per gallon (dw) =6.84
Total Capacity (AvGas) Fuel Load Weight=(Fuel weight)* (gw)
GPH=start fuelend fuel
Aviation Gasoline weight per gallon (gw) =6.00
Jet A weight per gallon (dw) =6.84