A method of testing and proving fuel efficiency improvements includes installing a telematic device in each of a first plurality of vehicles and a second plurality of vehicles. The telematic devices collect baseline fuel consumption data during a first time period and collect test fuel consumption data during a second time period. Between the first and second time periods, at least one operating parameter of the second plurality of vehicles is modified such that the baseline fuel consumption data and the test fuel consumption data can be analyzed to determine any fuel efficiency improvements caused by the modified operating parameter. To ensure reliable and statistically-significant results, each plurality of vehicles may include 15 vehicles and each time period may include 60 days.