I hope this is the right venue for my question. I'm trying to find the conversion factor between vehicular CO2 emissions (in units of mass, e.g. in metric tons) and the energy generated (in kWh).
If I understand correctly I found an emission factor for electricity on EPA's site - 7.44 × 10^-4 metric tons CO2/kWh.
I assume that the energy efficiency of an average car is different from that of the average power plant, so this will probably not be very useful to estimate the emission factor of vehicles.
I would greatly appreciate a source that could provide this conversion factor.