With stricter emission requirements and the rise of electrical powertrains, it would seem to be the internal-combustion engine’s days are numbered. However Engineering Defined host Jason Fenske believes inner combustion will reside on—due to new applied sciences.

Fenske is pretty optimistic in regards to the longevity of the internal-combustion engine, each due to the inherent energy-density benefit of gasoline over batteries, and due to efficiency-boosting applied sciences. On this video, he takes a better have a look at a few of these applied sciences.

One choice is homogeneous charge compression ignition (HCCI). An HCCI engine burns gasoline, however makes use of compression ignition—like a diesel engine—quite than a spark plug. In concept, that gives the effectivity of a diesel, with out the soot and excessive ranges of nitrogen-oxide (NOx) emissions. Nevertheless, it requires a lot finer management of the consumption temperature, in addition to the timing of ignition.

The subsequent choice is pre-mix cost compression ignition (PCCI). Fenske described it as a “center floor” between diesel-engine compression ignition and HCCI, as a result of it injects some gasoline early to let it combine with air within the combustion chamber, after which injecting extra gasoline later. That gives extra management over ignition timing than HCCI, however may also create pockets of unburned hydrocarbon byproducts, which is dangerous for emissions. PCCI engines even have a reasonably slim working vary, with excessive potential for knock below full throttle, Fenske stated.

Lastly, we now have reactivity-controlled compression ignition (RCCI). This makes use of two fuels: a low-reactivity gasoline (like gasoline) that’s port injected, and a high-reactivity gasoline (like diesel) that’s direct injected. “Reactivity” refers to a gasoline’s tendency to ignite below compression. This methodology results in massive effectivity good points, however nonetheless with pretty excessive emissions, Fenske stated. The complexity of utilizing two fuels might additionally make it a non-starter commercially.

These various internal-combustion engine designs will not be prepared for prime time, however automakers want to squeeze each ounce of effectivity out of in the present day’s gasoline engines utilizing extra mature applied sciences like direct injection. Fenske additionally coated one other doable future internal-combustion expertise—entry ignition—in one other video, which can be value trying out.