What is the advantage of that? Can the engine burn on a leaner mix of ethanol? A normally aspirated spark ignited engine seems much simplr. Using two fuels that must be balanced at varying loads seems like it could be quite a problem. I'm guessing that the ratio of the two fuels would not be a constant and would vary with pressure and temperature conditions. The computer would need to monitor both and compensate.
With controlled (probably common rail) fuel injection of both the ethanol and diesel modern electronics should easily be up to the challenge.
You will get superior fuel consumption because of the inherently higher compression of the engine than an equivalent naturally aspirated spark ignition engine.
I think another advantage is it removes any need to provide some sort of ethanol fueling network that is foolproof prior to rollout -as if you can't get ethanol you can just make it switch to a pure diesel engine until you get pure ethanol - whilst diesel would be consumed even if you were running on ethanol the minimum ratio is so low that a tank of diesel would last for a very very
I imagine it would also be more tolerant of water in the ethanol than a spark ignition engine as the ignition of a small amount of diesel is surer to be a far higher energy process than a puny little spark.
If the engine has trouble igniting the fuel because of "wet" ethanol the engine could detect that and reduce the ethanol:diesel ratio on the fly.
Are there emissions advantages? I used to have a Honda CVCC engine where a rich mixture of gasoline ignited a leaner mixture. It was supposed to be more environmentally friendly.
Apparently there are benefits, but I am not sure how it stacks up against an otto cycle engine on that basis.
Is the engine running under the Otto cycle or the Diesel cycle or some odd combination?
It is running in a hybrid where the compression ignition is used to ignite the Otto cycle fuel.
But in engineering terms it is certainly closer to a diesel engine than a petrol one.