Everything I have ever read contradicts this. Where are you finding tests that show higher octane in a standard, non-tuned engine, increases output?It is the minimum octane recommended. But the fact is the engine pulls less timing and makes more power on 93 vs 87, even on the stock tune.
Of course, you're a blind Honda disciple (same guy who says never use anything but 0W-20, which is dead wrong) - but minor hp gains can be had with 93 and it's cheap insurance on a turbo car if you're on boost frequently. With 87 the ECU just dumps more fuel to mitigate detonation, which contributes to fuel dilution of the oil.Premium fuel
87 octane is what Honda recommends for my 2.0 Turbo.
Premium and even 89 octane is a waste of money.
I couldn’t find anything there that referred to a standard tune engine. Here's an interesting comment on Quora that basically mirrors everything else I've read.Well documented, believe it was Hondata
That's interesting. Not sure why every other test I have read comes up with completely different conclusions. My own “seat of the pants” testing shows no improvement that I can feel, but not sure a 3-4% measured improvement could be felt.There are several dyno threads that prove the case e.g.
As promised: We ran down the 87 in our first tank of fuel and filled with 91. There was a little mixing, so it was not 100% 91, but it was a lot better than before. Roughly, you are looking at 9 HP and 11 lb-ft torque above 4000 rpm. But there is another way to measure what the computer is...www.driveaccord.net
Running 20 psi on 87 octane is completely insane in my opinion - combustion chamber temps go through the roof at those boost levels, little question the ECU just dumps tons of gas trying to keep it in check. This is basically an economy car and Honda knows their customer, but any other manufacturer running these boost levels doesn't recommend 87. Shell 93 only in my car - and 5W-30 Castrol synthetic, 0W-20 is too thin, especially a boosted motor with inherent fuel dilution
Ktuner has done dyno testing that confirms a small bump between 87 and 93 octane http://ktuner.com/accord-2l-extended-testing/Everything I have ever read contradicts this. Where are you finding tests that show higher octane in a standard, non-tuned engine, increases output?
I know the opposite is true, in that an engine designed for premium will retard timing slightly to prevent knock when standard grades of fuel are used ... but not the other way around. I'm curious to see which tests you found to support your point.