Publicly-traded truck companies like Sinotruk, and the publicly-traded makers of the diesel engines that power them such as Yuchai and Weichai, have very strong market positions in the China market and very bright futures as a result.

FORBES: China's Auto Market Keeps Booming

Some of the start-up engine companies say they could ultimately get orders from makers of power generators or boat engines.

WSJ: How to Make Better Car Engines

Makers of fixed-wing aircraft are also looking at diesel engines, in small planes at least, where they show promise as a serious alternative to standard piston engines, which run on a high-octane form of petrol.

ECONOMIST: Monitor