So, conventional wisdom is that if your engine is designed to run on 87 octane fuel, running higher octane fuel in it is a waste of money. Also, some higher performance turbo engines will run fine at 87 but you'll get more horsepower with Premium.
What i am curious about are the current turbos that are designed for economy over performance. My Google Fu is failing because I am getting mixed messages and most of what I find is just a fallback to convention wisdom. Then articles like
this imply that even economy turbos' ECUs can adapt to higher octane fuel and may produce more power.
I'm actually curious about this less about more horsepower and more about efficiency, wondering if maybe it's easier on the engine to not have to run slightly detuned? Where I am at, Premium is less than 10% more and wouldn't be a big financial hit as I only fill up once a month or so. I did experiment with ethanol-free Premium and saw about a 1.5 mpg gain but that costs almost a dollar more a gallon and just isn't worth it. Regular Premium is only 30 cents more a gallon so not as bad.
Anyone got any decent data for this?