In past years the Society of Automotive Engineers SAE published reports on road-testing protocols.
There recommendations were to do a preliminary warm-up cycle of at least 35-kilometers at a continuous 80 km/h in order to stabilize the tires and all lubricants at an equilibrium temperature,and in so doing,stabilize the powertrain losses.
Without the warming cycle,mpg numbers were penalized until the vehicle reached 'equilibrium.'
I wasn't sure that you might be doing this during tests.Just wanted to mention it.
