Automotive transport represents one of the highest contributing sources of oil use, local air pollution, and greenhouse gas emissions. Several countries, notably including several European countries and China, have proposed bans on the sale of automotive internal combustion engine (ICE) vehicles as a means to abate these negative effects from the sector. Some cities and regions have already instituted restrictions on ICE vehicles. Larger, national bans have been discussed as a policy to begin in 2040. We consider the literature on proposed policies to ban ICE vehicles and develop scenarios to estimate the potential impacts of these proposed bans, to contribute to a peaking in oil demand and eventual reductions in CO2 emissions. We find that national level ICE car bans in key markets such as China and Europe in 2040 could reduce oil use by five million barrels a day (b/d) by 2050, under five percent of projected global oil use. A global ban would eliminate three times that level of oil use but would likely take several decades for its full impact is realized. Our findings suggest that other supporting policies beyond the bans alone might be necessary to trigger more rapid changes in markets and purchase behavior.