HCCI types and why

With the importance of global warming to not do any more
damage a change to a good source of the damage being caused needs
to be changed. So less vehicle emissions is needed.

So for me I see it for a win to "cut back" your spark plugs.
Or get a side gaped type plug for your engine.
Burring more fuel makes more power anyway along
with better MPG and helping on emissions.

Other than spark plug types in that I would like to see more
work done on their usage for better combustion for lower
emissions and MPG. More side gaped plugs types used
and higher voltage for the combustion in designing the engine
done by the automakers.

For engine makers there has been a push for HCCI engines.
Those engines are up in a higher emission standard and efficiency.
In America HCCI engines are coming out. Also Japan are working
on a type. A HCCI type engine in a semi truck would help in
delivery cost for small businesses. (Walmart makes $500 billion a year
fuel for trucks is not a issue.)

~~~~~Exploring the Next Frontier in Efficiency with the
Opposed-Piston Engine.
The Achates Power Opposed Piston Engine delivers
a demonstrable incremental improvement in brake
thermal efficiency compared with the most advanced
conventional four-stroke engines. With the
elimination of components such as the entire
cylinder head and valvetrain, the Achates Power OP
Engine is also less complex and costly to produce.

After a brief overview of the opposed-piston
architecture’s inherent efficiency benefits this
technical paper features detailed performance and
emissions results of a multi-cylinder 4.9L Achates
Power opposed-piston engine tested on
dynamometer and configured to meet current
commercial truck requirements.

The second part of this paper presents the results
from testing various transient test-cycles on the
multi-cylinder 4.9L engine including aftertreatment
performance.

After a brief description of a light duty engine
concept and how it improves fuel consumption by
30% over an advanced light duty diesel 4-stroke
engine the paper discusses the next step in
technology development for the OP engine:
The gasoline compression ignition opposed piston
engine.
http://achatespower.com

~~~~~Mazda announces breakthrough in long-coveted engine technology
A homogeneous charge compression ignition (HCCI) engine ignites petrol through compression, eliminating spark plugs. Its fuel economy potentially matches that of a diesel engine without high emissions of nitrogen oxides or sooty particulates.

Mazda's engine employs spark plugs under certain conditions, such as at low temperatures, to overcome technical hurdles that have hampered commercialization of the technology.
https://www.reuters.com/article/us-mazda-strategy-idUSKBN1AO0E7