Ignition, BioPower
Other ignition timings are required with ethanol mixture due to other properties of ethanol as fuel. For this reason, a further matrix has been added for ignition timing with E85 operation.
With adapted ethanol contents of 0-5% the table for petrol operation is used, while at 80-85% the new table for E85 is used. With ethanol contents between 5-80% the torque varies steplessly between the two tables.
The high octane rating in ethanol enables the additional use of slightly advanced ignition in many operational cases. This results in an improved combustion efficiency and lower exhaust temperature. The increased combustion efficiency means that fuel consumption can be reduced slightly with high ethanol content. The lower exhaust temperature means that fuel enrichment is not required below 4500-5000 rpm (depending on engine variant).