I have been keeping track of the fuel-consumption of my car ever since RON95 was introduced into the system. I began my measurements about two months before switching over to the new fuel. The method used is similar to the one used before. The results are both anecdotal and empirical. The RON95 fuel is more fuel-efficient than the RON97 fuel was before. This is illustrated by the chart above – the bars on the right are generally higher than the bars on the left.
So, there is no real reason to pump the RON97 fuel anymore. The RON95 fuel costs 10% less and delivers about 10% extra efficiency.