Subject: Why did more simple engines not impose themselves in the [car] industry

The conventional 4 stroke- , Diesel-  and 2 stroke-engines are quite 
complex, delicate and inflexible machines when we figure out how the motion 
is transformed from linear to rotational, how valves and ignition must be 
timely controlled, how the engine is cooled, how it is lubricated etc. 

I would like to know why apparently more simple, more flexible, more 
resistant engines, like Turbines or Jet engines did not impose themselves 
in the [car] industry.  Please do not invoke only the historical reason. 

Thank you.

Re: Why did more simple engines not impose themselves in the [car] industry