Fuel properties, E85: General
E85 is a mixture of 15% petrol and 85% ethanol. Ethanol has the formula C2H5OH and accordingly differs from petrol as it is one substance and not a mixture of several. Ethanol is an environmentally friendly fuel as it does not add new carbon dioxide to the cycle.
Exposure to ethanol is less dangerous to petrol. E85 must be handled with the same caution as petrol.
Ethanol has the following properties:
- conducts electricity
- dissolves in both water and petrol
- freezing point -144°C
- boiling point +78°C
The weight is slightly higher than for petrol, 0.789 kg/l versus approx. 0.740 kg/l for unleaded 95 octane (RON) petrol.
The energy content of ethanol is 23.7 MJ/I compared with approx. 33.1 MJ/I for petrol. There are different proportions of ethanol in petrol on the world market, although E85 is so far the most common. The reason why E100 is not used is because it is difficult to start an Otto engine with conventional technology at temperatures around +5 degrees C.
E85 is colored red so that it can be easily distinguished from pure petrol for example.