Some engines use a spark to ignite their fuel, and others rely on compression. What does all of that mean? And how do the two kinds of engines differ?

HCCI engines have a compression ratio of 12:1 (similar to that of a conventional direct-injected gas engine), so they can run on regular pump gas and E85.

What is compression ignition? Compression ignition basically is the term that is used for describing the manner in which diesel engines function.

Applying a suitable design optimization technique is a crucial task for optimizing compression ignition engines because of the time-consuming process of optimization even with advanced supercomputers.

The efficiency benefits of entry ignition include the ability to use a higher compression ratio than a standard gasoline engine, a lean air-fuel ratio.