I've test driven a number of cars the past week, and what I've seen is a cautionary tale on mapping technological trajectories. Two decades ago Automotive News launched the PACE Award to recognize innovation by suppliers. At the same time, the Partnership for a New Generation Vehicle (PNGV) set out to develop, well, the next generation of vehicles. What would be needed? Exotic materials, new propulsion systems, on and on. Yes, the steel industry came up with a light steel frame project, but the sense of the time was that aluminum, magnesium and fiber-reinforced materials would be central. On the drivetrain side, the future would lie with all-electric vehicles running on hydrogen fuel cells. Transmissions – well, electric motors wouldn't need one. For legacy combustion engines, however, the direction was CVTs (continuously variable transmissions).
Instead what we have are "standard" gasoline ICEs (internal combustion engines) that deliver 40+ mpg in a mid-sized car, with additional gains come each full model change. Turbos, direct injection, improved valve timing, all drawing upon sensor and computing power, have improved the combustion end. New bearings and friction materials complement that, alongside lots of little energy-saving steps – electric fans and eSteer that lessen parasitic losses are one example – cumulate to real savings. On the transmission side we will soon see 9- and 10-speed transmissions that use tried-and-true architectures and gear systems to deliver gains comparable to CVTs, enhanced by electronically-controlled shifts. Meanwhile metallurgy continues to advance, with hot stamping of "soft" steels into high-strength steel finessing the formability challenges to enable using lighter, stronger but still inexpensive steel. Finally, while not prominent in the US, at least for passenger cars, CNG and diesel (pervasive in Europe) and biofuels (ethanol in Brazil) provide greater flexibility and lower emissions alongside higher efficiency.
[Diesel, as a heavier product that needs less refining, should cost less than gasoline ... and in engines the new low-sulfur product can now run cleaner than gasoline. Sigh...]
Not all of this was wrong. What we see today is a greater palette of techniques and materials. The Ford F-150 will retain a steel frame, but shift to an aluminum body. Electrification of vehicles continues, as with eSteer. Start-stop systems bring much of the gains of hybrids at lower cost and complexity. Some companies have chosen CVTs over dual-clutch multi-gear automatic transmissions; they don't dominate, but haven't vanished. The one piece that seems wide of the mark is the (hydrogen) fuel cell, which with hindsight flies in the face of the economies of scale of electricity generation, while still requiring batteries: better just to use more batteries. At the same time, a totally new angle are connected vehicle and autonomous technologies that (as with adaptive cruise control) can perhaps improve traffic flow and save energy that way. Meanwhile, policies to lessen emissions and improve safety have gone much further than anyone imagined in 1993, when PNGV was launched. Both "cost" fuel efficiency, making the gains achieved to date surprising – in my Cruze I've peaked at 50.9 mpg over 25 miles.
Now in the long run I think battery electric vehicles will dominate. There has however been no breakthrough in battery technologies, only gradual improvements in power-per-weight and gradual reductions in cost. So as fossil fuel prices continue to rise – global growth dynamics are strong over the medium run, so higher demand will dominate improvements in extractive technologies – BEVs will gain traction. It will not however occur quickly. Meanwhile, as a perusal of PACE Award recipients demonstrates, lots of little steps continue that continue improving legacy ICE technologies.