Diesel fuel is a natural lubricant. It WILL NOT cause cylinder scoring under ANY normal operating circumstances.
Thanks, that's an important note. However, scoring may still be caused by the carbon buildup and improperly seated rings.
Simply put... if you use low octane fuel in a high-performance engine, you will experience detonation more quickly than when using high octane fuel.
Yes, provided that combustion conditions are the same, which is not the case. In a relatively low-compression engine without high-pressure injectors and with a rich mixture, combustion of the diesel fuel is likely to occur heterogeneously (i.e. at the interface of gas and liquid phases) and with a shortage of oxygen, strongly reducing potential detonation. I am not saying it will not occur, but it is much less likely than predicted from the fuel characteristics alone.
Diesel fuel contains much more energy than gasoline/petrol.
Roughly 14-15% more per litre, mostly due to higher density. Energy per kilogram is almost the same.
This is the reason diesel engined vehicles get better economy than gasoline/petrol-fuelled vehicles.
Wrong. The main reason is that from the thermodynamic viewpoint, Diesel cycle is more efficient than Otto cycle (due to being closer to Carnot cycle).
It also contains a vastly increased amount of carbon and other pollutants.
The content of carbon in the organic compounds is almost the same in all motor fuels. However, diesel fuel produces a lot more soot (elemental carbon) due to incomplete combustion.