According to the DOE, plug-in vehicles on US roads displaced 323 million gallons of gasoline in 2018, or about 0.25% of all gasoline used in the US that year.
Gasoline displacement from plug-in vehicles in 2018 was about 42% higher than in 2017 and about twice as much as 2016. Displacement from all-electric vehicles is also growing. The gasoline displacement from EVs versus PHEVs was split almost evenly in 2012 and 2013, but by 2018 EVs accounted for two-thirds of all displacement.
As EV adoption continues to grow, the amount of electricity consumed by plug-ins in the United States has nearly doubled in the last two years, from 1.44 terawatt-hours in 2016 to 2.85 terawatt-hours in 2018. The share of electricity consumption from all-electric vehicles increased compared to the electricity consumption from PHEVs. In 2018, EVs accounted for 61% of all electricity consumption from plug-in vehicles, while PHEVs accounted for the remaining 39%.
Source: Office of Energy Efficiency & Renewable Energy