ZEV – means Zero Emission Vehicles. Any vehicle which is certified by the Executive Officer of the California Air Resources Board to produce zero emissions of any criteria pollutants under any and all possible operational modes and conditions.  Incorporation of a fuel-fired heater shall not preclude a vehicle from being certified as a ZEV provided the fuel-fired heater cannot be operated at ambient temperatures above 40 degrees Fahrenheit and the heater is demonstrated to have zero evaporative emissions under any and all possible operational modes and conditions.