To boost fuel efficiency more diesel engines are popping up, as well as improved four-cylinder engines.

为了提高燃料效率，更多的柴油发动机和改良的四缸发动机应运而生。

youdao

This paper introduces the process of repairing hydraulic cylinder by using boring and rolling combined working technology, working quantity is steady and production efficiency is high in this method.

介绍了用镗滚压复合加工技术修复液压缸筒的过程，此法修复缸筒质量稳定，生产效率高。

youdao

The utilization of the pressure wave in the intake pipe and exhaust pipe which not only make more exhaust gas out of the cylinder but also improve the charge efficiency and make more fresh gas.

合理的利用进、排气管中的压力波，不仅能使更多的废气排出缸外，而且还可以提高发动机的充气效率，使尽可能多的新鲜工质充入。

youdao

The 4-cylinder vans will get a combined fuel efficiency of 25 miles per gallon, nearly double what the Ford Crown Victoria gets.

FORBES: Nissan To Be Next Supplier of New York City Taxi Cabs

Now, it's true that amazing gains are being made in the efficiency of internal combustion engines, both gas and diesel: direct injection, cylinder deactivation, stop-start, eco-mode throttle mapping, to name a few of the recent applied technologies.

WSJ: Ford C-Max Hybrid Energi: The Bawdy Electric