ExxonMobil published a study with an long term outlook for the usage of energy up to the year 2040.

Cars become more energy-efficient and the personal vehicle fleet shifts from conventional gasoline and diesel to more hybrid models by 2040

The global personal vehicle fleet doubles over the Outlook period, from more than 800 million to more than 1.6 billion. As more energy-efficient vehicle options become available, conventional gasoline and diesel engine vehicles will make up a smaller share of the fleet over time, down to around 50 percent in 2040.

Around 2025, ExxonMobil expects hybrid vehicles will be less expensive and their share of sales will expand quickly, adding more efficiency to the fleet. Full hybrid vehicles will make up about 40 percent of the fleet in 2040, or more than 50 percent of new car sales in 2040. In the latter part of the Outlook, electric and plug-in hybrids (utilizing a gasoline engine and battery-powered motor) will begin to play a more significant role, making up around 10 percent of new car sales in 2040, or about 5 percent of the fleet.