quite alot The US actually has the largest estimated reserves in the world if include shale oil. The U.S. has 2% of the worlds oil. By the estimation of BP and others there are 40years of oil left. USGS says we hit the peak in 2034 from there on out it gets harder to get and more expensive. Shale oil takes a lot of hydrogen to produce crude the pollution from making hydrogen puts a lot of co2 in the air. Essentially everyone agrees that in 40 years we better be depending on something else. interesting articel and net sim to figure your own projection at electric and hybrid car dot com.