V Power

[ainarssems]

You can tell the ECU has changed fuel maps onto a lower profile to suit the fuel.

Just a little explanation. ECU does not change fuel maps and does not have ability to change maps on it's own. It's what tuners do. Fuel trim is changed on demand depending on feedback from O2 sensors. ECU also stores learned value by how many % fuel trim should be adjusted in idle and part throttle. This ids further trimmed on the fly depending on conditions

Where RON comes in is if it is too low and engine starts knocking it retards ignition timing to prevent knocking. This also happens on the fly depending on feedback from knock sensors. If you fill with good fuel again and it is not knocking it does not retard ignition any more. This depends also on carbon buildup in compression chamber, spark plugs, vacuum leaks and other factors. Also if knock sensor bolts are over-tightened knock reading will be higher or if you have something loose banging on the engine. I have logged my S8 and it almost never retards ignition with V-Power, with regular 95 it only does it occasionally under heavy load. M8tes 3.7 on the other hand retards ignition with 95 on the slightest acceleration and on 98 it still retards on heavier acceleration even if 3.7 have lower compression.