How to read this: On the Savings Map, green states are where an EV costs less to fuel than the selected gas car; red states are where gasoline is cheaper. The metric is savings per 100 miles = (gas cost) − (EV fuel cost). On the CO₂ Map, green states show where driving the selected EV avoids the most CO₂ compared to the gas car; lighter shades indicate smaller reductions. The metric is kg CO₂ avoided per 100 miles = (gasoline CO₂) − (grid electricity CO₂). Gasoline emits 8.887 kg CO₂ per gallon burned (GREET). EV emissions depend on each state's electricity grid carbon intensity. At-home charging uses EIA average residential electricity rates by state for January 2026. Public charger uses AAA average Level 2 / DC fast-charging prices by state (March 2026). Gasoline prices are AAA state averages by grade (March 2026). EV charging calculations assume a standard 90% efficiency rate to account for energy lost as heat. The Payback Calculator assumes maintenance costs of ¢9.59/mile for gas cars and ¢7.94/mile for EVs. Important: The Savings Map and Table compare fuel costs only — they exclude vehicle purchase price differences, maintenance, insurance, and other ownership costs.