The government's Energy Information Administration released its 2014 Annual Energy Outlook report, which had plenty of nuggets on what it expects Americans to drive between now and 2040.
EIA expects overall vehicle-miles traveled to increase, on average, 0.9 percent between 2012 and 2040 — down significantly from the 1.2 percent annual projection over the same span in the EIA's 2013 outlook.
Still, the agency projects overall vehicle fuel efficiency to improve 2 percent per year as newer cars replace older ones. That means cars should average 37.2 mpg by 2040, up from 21.5 mpg in 2012, and it "more than offsets" the increase in vehicle-miles traveled.
The upshot is that America's cars will use less energy (including fuel) in 2040 even as vehicle-miles increase; that's a shift from the average 1 percent annual growth rate between 1975 and 2012. Don't confuse the mileage with corporate average fuel economy mandates, which stipulate 54.5 mpg by 2025. CAFE measures unadjusted (not window-sticker) mileage in new cars sold, not all cars currently on the road.
Don't expect plug-in cars and hybrids to take over, either. EIA expects conventional gasoline engines — not hybrids, flex-fuel (E85) engines, diesels or plug-ins — to account for 78 percent of the new cars sold in 2040, which is down just slightly from 2012's 82 percent. But those won't be the engines of today. EIA projects 42 percent of those 2040 sellers to have so-called "micro hybridization" attributes like regenerative brakes or idle stop-start systems. Of the 22 percent of 2040 sellers that aren't conventional gasoline (micro-hybridized or otherwise), 11 percent will be flex-fuel cars, 5 percent will be full hybrids (up from 3 percent in 2012) and 4 percent will be diesels (up from 2 percent). EVs and plug-in hybrids will account for the remaining 2 percent (up from nearly zero percent in 2012).