Diesel Fuel

Boiling range/boiling temperature of summer diesel/winter diesel

	Cetane	Calorific value	Density at 15°C	Sulphur
Diesel	from 51	42.800 kJ/kg	0,82 - 0,84 g/cm³	<350 ppm
Super-Diesel	from 58	42.800 kJ/kg	0,82 - 0,84 g/cm³	< 10 ppm

Function

Also in case of low temperatures and a low compression ratio, (causing fewer nitrogen oxides in the exhaust gas) starting the diesel engine should not be problematic due to a special ignition willingness and a low maximum boiling temperature. To ensure noise reduction, a short ignition delay is important. After successfully starting the cold engine, the fuel filter should not clog. It is desirable to have low sulphur in the exhaust gas, because of the exhaust gas treatment. The life span of the injection system can be significantly elongated with a good lubrication. These characteristics should be guaranteed in all countries in a norm and be kept with as few deviations as possible.

How it works

Diesel is distilled like petrol mostly of oil. However, diesel can also be won of natural gas, liquefied petroleum gas or consist of biological diesel fuel. Mixtures are possible, too. The higher ignition willingness compared with gasoline is reached by lower interlinking of the chain-shaped hydrocarbons. Additives, for example flow improvers, are added to the diesel during the winter in order to lower the pour point. Diesel can become viscous at low temperatures by elimination of Parafin, and block the filter.
The mixture for the petrol engine should be less prone to ignite than the mixture for the diesel engine. Therefore, diesel should have a high cetane number. The self-ignition temperature for compressed dieselis at most approx. 400°C and for petrol minimally approx. 500°C. The flash point of diesel lies at 55°C. Thus, diesel belongs to danger class AIII.

Wrong fuel

It might happen easily and there is up to now still no real protection against putting the wrong fuel. Maybe sometime soon there will be a system that recognizes wrong filling up with petrol instead of diesel fuel. If you notice that the engine produces different noises, it might be too late already. Best of all, a diesel engine with gasoline should not be ignited at all. The more modern the Diesel engine, the more damage the petrol will cause to the complete high-pressure arrangement of the diesel injection system due to its lack of lubrication qualities. The reparation might be more extensive than replacing the short block assembly. Therefore, a wrongly refuelled diesel vehicle should be dragged to the workshop.

Important

Diesel is not cheaper, but more expensive in the extraction and production than petrol. The price difference results from a substantially lower tax. This has originated from a subsidy for the transport trade.

Specific heat value

The specific heat value of diesel lies with 42,500 kJ/kg somewhat below that of normal petrol.

Special feature

There are utility vehicles, which use even the diesel fuel for cooling control units.