GEN 2 Gas Octane Question

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500mag

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I've had 12 month old 93 octane run through a high boost engine and there was no knock whatsoever. According to your math it should have been down to 81 octane at that point. Do you mean one "point" or 0.1 per month maybe? I don't disagree with you overall, over time you do lose the lightest parts of the fuel which tend to be the ones with the best anti-knock properties. With the sealed up fuel systems these days, it's not actually lost, but it all ends up in the charcoal canister and not in the actual fuel being dumped into the engine at high rates under WOT.

Article on octane degradation: 87 is more susceptible than 93. One point per mo was just a crude rule of thumb that a marine mechanic told me years ago. https://www.sunocoracefuels.com/tech-article/octane-stability-high-octane-vs-low-octane-fuels
 

WRCRaptor

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What? Typically you run higher octane to reduce chances of knock and preignition on engines with high compression ratios and forced induction. Why would the injectors care what the octane is?

I heard if you put 85 octane in, your gas tank falls off. :)

I know, the service dept has noting to gain in recommending encouraging higher octane. It was no big issue for us.
 

EricM

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We had a brand spanking new 2018 Outback as a rental for about 6 months during the Takata recall. My wife hated it. So did I. It rode rough, had all kinds of weird drivetrain noises, the dash layout sucked, the CVT sucked, the throttle was "all in now, then nothing", it was just a total **** all the way around. Plus it was ugly as sin. It was a great day when we got our Ford back and left that thing in their lot. Maybe we had a dud, but man, it really sucked. It amazed us both that they litter the roads the way they do after driving one for so long.
 
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