At the end of the article, it talks about a shipping company wanting to retrofit their fleet. Might be possible.
What shipping company is using a gasoline engine requiring spark ignition instead of diesel that ignites under compression?
Except diesel engines don’t have spark plugs.
The most efficient engine might be a diesel-gasoline hybrid.
http://www.gizmag.com/gasoline-powered-diesel-like-engine/22608/
Except that most shipping companies use vehicles with diesel engines. And diesel engines do not require a spark-producing ignition system