Have been hearing a lot lately how all these 10-15 % ethanol blend fuels are bad for older engines. 2002 2.5 here. Usually run regular Chevron but tried 94 as it said ethanol free. Now I have also heard that higher octane won't make any difference in my engine, just wasting money. But it did seem to drive better and have a touch more power. Would this be due to the higher octane or the no ethanol? Thanks in advance for any replies