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  • Since my engine is heavily tuned to specifically maximize power output on 91, I have to use at least that with no exceptions (unless I map my engine back to the stock mapping).

    1 month ago
    2 Bumps
  • Fuel science “good news” depends on what you drive. Non-performance Engines (yes even your V8, it only revs to 7k) made after 1985 generally have the design to handle “87”/low quality fuel and, all else maintained well, will still get you hundreds of thousands of miles from the engine - if anyone tells you otherwise they are selling you gas or guzzle marketing koolaid. When the engine compression numbers rise, along with the redline (engine speed), that’s when it gets more serious to put in what “the manufacturers” recommend (crazy, they are in bed with fuel producers! Who would have thought?!). Many also believe to “pamper” the whole car when new for a few thousand miles to allow everything to heat/settle correctly.

    Obvioulsy, actual race cars (no, your off-dealership-floor sports car, even with 700hp, is not a competitive race car - unless you bought Mazda’s caged FIA Miata) have a specific fuel mix the engine is designed for so they must fuel with that exact fuel.

    So, if you’re “moving down” on an M/AMG/RS/Z06/Roush/etc you’ve been driving for a while, you’ll be fine and save some money, even do yourself a favor and stay there unless you psychologically feel like the higher octane is “doing something” (actually it’s just the ECU leaning out fuel “consumption” a tick for the power you ask because it sensed more efficient fuel - which studies have shown reduce mpg IRL because ppl then just develop a heavier foot). Your contemporary performance cars will be fine... until you put in a tune/mod on it and push the engine parameters “out” of what it was designed for, then fuel/oil quality becomes exponentially important.

    1 month ago
    4 Bumps
    • Wow! 7k rpms in a V8. Great advice there Daniel!

      1 month ago
    • How high an engine will rev doesn't have anything to do with ignition phase and/or compression. If manufacturer specifies a "high" octane as required rather than recommended - it...

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      1 month ago
      2 Bumps


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