No, the ECM does not adjust for fuel quality - the recommended fuel is typically 87 octane non-ethanol and 89 ethanol blended - concentrations of more than 10% ethanol can damage fuel system components (89 octane is recommended for ethanol blended fuel because 89 is 85 octane blended appx. 10% with 100 octane ethanol to attain 89 octane. Ethanol reduces power (just like 110 octane aviation gas does) but ethanol also reduces fuel economy, damages plastic and rubber components in the fuel system and draws moisture causing the ethanol to separate from the gasoline. You can safely run 91 to 93 octane pump gas, but there is no performance improvement in doing so. Higher octane fuels typically have lower concentrations of ethanol.
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