The amount of energy used in the economy per real dollar of GDP, “Energy Intensity”, has been steadily dropping and is now about half what it was in 1950. So a barrel’s worth of oil in 1950 now stretches to two barrels worth of work.

This is before the coming hybrid capital turnover in the transportation sector to double the efficiency there. So I guess prices will have to nearly double again to curb energy use like the 1970s oil shocks.