Ford Probe Owner's Manual page 213

Fuel Economy
Fuel economy is an estimate of the efficiency of
your vehicle and can be calculated as Miles Per
Gallon (MPG) or Liters Per 100 Kilometers
(L/100K).
Do not calculate fuel economy during your
vehicle's break-in period. This would not be an
accurate estimate of how much fuel your vehicle
will normally use.
To calculate fuel economy:
1. Fill the tank completely and record the
initial odometer reading.
2. Every time you buy fuel record the
amount (in gallons or liters) purchased.
3. After at least three to five tankfuls, fill the
fuel tank and record the final odometer
reading.
4. Use these equations to calculate your fuel
economy:
English: MPG = (total miles driven)
(gallons used)
Metric: L/100k = (liters used)
(100 kilometers)
Comparisons With EPA Estimates
EPA fuel economy figures are obtained from
laboratory tests under simulated road conditions
and may not reflect the actual conditions you
experience or your style of driving. The EPA
fuel economy estimate is not a guarantee that
you will achieve the fuel economy shown.
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