An Octane Question

courtesy of Bob, The Auto Answer Man

I have a '93 Camry that the manual says requires 87 octane or higher. Most places I've lived that was the regular grade. Where I live now, the regular grade is 85, mid 88 and premium 91. Would it be safe to use the 85 (is it just a calculation difference like only reporting MON, not R+M/2) or do I need to use the 88?

Hi John,
Motor Octane number (MON) would be a lot lower than 85 if that is all they were reporting. Do you live in an area that has a different altitude than where you lived before? If the book calls for 87, that means the ignition timing has been adjusted for that type of fuel (there are other factors, but ignition timing is the main). Going one unit higher will not hurt anything, but going lower may cause some run on or pinging.
Good Luck!
Drive Safely!
Bob, The Auto Answer Man

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