Some cars are more efficient with fossil fuels than others, but there are advantages and disadvantages to all types.
Choose the most efficient car that fits your needs and then observe some habits that can help burn less fuel and energy as you drive.
Calculate your own gas or electric charge mileage:
Fill your gas tank full.
Record the odometer (total miles your car has driven) reading from your dash.
Drive as your normally would over a period of time until your gas tank is nearly empty.
Fill your gas tank full again and record how many gallons of fuel it took to fill the tank.
Also record the odometer miles from your car again.
Calculate the miles you drove. (1st odometer reading - 2nd odometer reading = ? miles) (Example: 56,101 miles - 55,750 miles = 351 miles)
Take the number of miles driven divided by the number of gallons it took to fill your gas tank up the 2nd time. (Example: 351 miles divided by 14 gallons = 25.07 mpg or miles per gallon)