I don't know about factories... we must enter in theories... but in the end they would be forced to build what consumers demand.
About the "discipline" it has nothing to do with "science".
In all this debate diesel vs petrol one thing ppl ignore is RPM, as if its free a given not a factor.
As example it would be fair to compare 2.4L F1 petrol with a 5.5L V12 Le Mans diesel ?... perhaps... but only if we give the diesel 6L or something (lol), the reality is that a F1 V8 2.4L has at any time more fuel burning, more power strokes than a Diesel V12, it consumes more fuel either per volume or gavimetry. It can do up to 20k RPM and average between 14 and 16K RPM, while diesel average less than 4K RPM.
Fairness ? yes...
lets restrict petrol to 5K RPM, which is already above what diesel can do... then pretty much invalidates petrol as a racing engine lol
Just for "comparison"
with the same fuel consumption, the same fuel flow... at 5K RPM (it could be possible for diesel), and as "leaked" a V12 pushed hard could have 1400Nm, a more modern efficient optimized could have 1500Nm, and at
5K RPM...
http://www.convertunits.com/from/ft+lb/to/N+m ( 1500Nm = 1106.343ft-Lb)
http://www.calculatoredge.com/new/horsepower.htm
... that V12 diesel will have more than 1000 HP... and almost the double torque(almost triple compared with that F1 2.4L)... a "very" severe beating lol
( in perspective to our road cars and factories, transmissions would have to be completely different... which now they are not... not really... (diesel would always be faster in 0-60mph) )