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 190,000,000 vehicles, approximately the total number of highway registered light-duty vehicle in the U.S. in 2013. In other words, full fleet conversion to electric. t0 = 2045.7 under this projection (the inflection date in which 50% of saturation would be met under current growth.