Currently, the fuel consumption data under the EnerGuide is based on testing requirements that use two test cycles, a highway test cycle and a city test cycle. The Minister of Natural Resources announced that they'll be moving to testing requirements that use five test cycles. The three additional test cycles would take into account the use of air conditioning, cold temperature operation of the vehicle, and also more aggressive driving. These amendments ensure that the green levy would continue to be determined by reference to the two-test cycle information, and not the new five-test cycle information, to ensure that the green levy continues to apply in the same way.
On May 16th, 2012. See this statement in context.