My P11EE CEL at 41k miles on 2018 OR

87 octane and WOT are not a good combo.

 

You're saying I can't expect to be able to WOT my engine with the recommended fuel grade? That is news to me, can you elaborate at all?

 

He can't; its fine to do so.

 

No relation to your issue.


87 makes the cylinder pressures rise more than higher octanes, even though the motor is retarding ignition timing. I see the difference in saws as I take apart/split these engines quite a bit. I quickly can tell when 87 is being used as far as gunk/scoring.


Now don’t get me wrong, I love this engine also. I play just the same. But “I try” to stay within the limits. 91 or above is one of them. Most importantly during the Summer months.


As we know, this motor loves it up top when piston velocities are at their fastest. What are the key factors for an engine? Heat and piston rings. These motors do see misfires. So add an Italian job at the pedal, I wouldn’t doubt scoring at the rings someday if the conditions are present, which leads to scoring at the cylinder walls. All no bueno for compression, most particularly the longevity of the rings.


Aside from your post OP, I sure as hell won’t rely on an 87 “recommendation” coupled with the motor oil’s shelf life past due or nearing when feeling spirited on a hot day.


However! How can we not feel this way, when 3rd Gems are known to pull out 18 wheel semis…must be some phantom torque :0)