Projected S-curve total number of electric vehicles in use in the United States based on current data from the EIA. Saturation is assumed to be 250,000,000 vehicles, the total number of highway registered vehicle in the U.S. in 2013. In other words, full fleet conversion to electric. t0 = 2047 under this projection (the inflection date in which 50% of saturation would be met under current growth.