Each region plays to its experience and strengths. European consumers moving from manuals to DCTs find them appealing, while Americans long accustomed to torque converters and smooth-shifting automatics find at least some DCTs jerky and unpleasant.

Most automotive enthusiasts disdain CVTs for their pulley-like power delivery, but they are well-accepted throughout Asia for efficiency and low cost. CVTs also are embraced by drivers of popular hybrid-electric vehicles such as the Toyota Prius.

Most observers say advanced electronics eventually will improve drivability and help DCTs and CVTs win converts in the U.S. and elsewhere. Meanwhile 8-, 9- and even 10-speed automatic transmissions will enable Detroit automakers to significantly improve fleet fuel economy.      

From an engineering perspective, gasoline engines and diesels will start to take on each other’s characteristics. One little-known development is a “downspeeding” trend for gasoline engines aimed at creating high torque at low rpms at the expense of peak horsepower. The goal is a fatter torque curve and better drivability, but it will result in less ponies and a lower redline for the marketing department to brag about.

Gasoline compression ratios also are steadily rising for greater efficiency and more low-end torque, while diesel compression ratios are headed in the opposite direction to reduce oxides of nitrogen emissions. Each year, gasoline and diesel compression ratios are getting closer.

Concerns that diesel engines would be forced out of the marketplace by upcoming Euro 6 and U.S. LEV 3 emissions standards have been eliminated by diesel particulate filters, selective catalytic reduction systems and higher injection pressures, Continental’s Breuer says.

However, tough new limits on gasoline particulate emissions defined by Euro 6C rules beginning in late 2017 have automakers scrambling to modify their direct-injection systems. “Everyone is working to avoid a gasoline particulate filter,” Breuer says.