The emissions from the Average Australian vehicle is about 200 gCO2e/km. For the 2 million passenger vehicles averaging 14,000 km per year here in WA, conversion of the WA passenger car fleet could save 5.6 million tons of CO2 per year if 100% renewable energy was used.
Even if EVs were charged from the current WA grid (currently over 80% fossil fuels), emissions would still be lower than petrol and diesel and would make for a saving of about or 2.5 million tons.