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Low speed pre-ignition, which can be catastrophic.
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.Low speed pre-ignition, which can be catastrophic.
Sounds like spark timing. Years ago cars routinely pinged in fact the cab drivers often used the cheapest gas they could get and they pinged half the time but I would do a diagnostic test on it.I'm trying to figure out if it's really an issue, and if so, how big of one. Mostly seems to happen at low rpm, upper gear, open throttle conditions.
OK, I knew I would be wrong sooner or laterNot timing related. Cylinders develop hot spots at low rpm and boost which causes preignition.

So what is the cure for this phenonium ?07navi, look up LSPI on wikipedia. It is an abnormal condition which occurs on direct injection super (turbo) charged engines (occasionally) under low RPM high load conditions. It is DETONATION caused by a cylinder hotspot igniting the intake charge explosively and prematurely and has nothing to do with normal ignition timing. It can cause catastrophic piston / connecting rod failure. It could have been an issue on '15 to '17 expys and earlier F150s as the addition of port injection seemed to remove the condition.
I did further research and found that reformulated motor oil which the name brands are now doing makes the problem disappear, so I am no longer concerned.
Recommended? By whom? Engine runs fine on the fuel it's designed for -- 87 octane. Undeniable it has more power with more expensive and needless higher octane but that's a different question. 93 octane isn't mentioned at all.No, because I run the recommended 93 octane
-- ChuckYour vehicle is designed to operate on
regular unleaded gasoline with a minimum
pump (R+M)/2 octane rating of 87.
...
For best overall vehicle and engine
performance, premium fuel with an octane
rating of 91 or higher is recommended. The
performance gained by using premium fuel
is most noticeable in hot weather as well
as other conditions, for example when
towing a trailer. See Towing (page 202).
Recommended? By whom? Engine runs fine on the fuel it's designed for -- 87 octane. Undeniable it has more power with more expensive and needless higher octane but that's a different question. 93 octane isn't mentioned at all.Yeah, I'll fill with 93 when towing my travel trailer in the summer but otherwise don't bother.
Ford:-- Chuck
Premium is only recommended for specific conditions, not as a universal fuel. Performance is more than adequate with 87 octane, "best performance" is only needed occasionally. 60¢/gallon additional cost for 93 here regardless of what 87 sells for.
-- Chuck
Lol.... I was undefeated up until last weekend heading to my WV getaway cabin. My wife and I noticed two trucks up ahead running side by side trying to taunt each other behind traffic on a 2 lane. The one truck was a loud Ford King Ranch 6.0 Diesel with a monstrous pipe that was rolling coal every chance he got, and the other was a newer half ton Silverado. I snuck up and pulled the Chevy when traffic cleared and got between the two going back to single lane. I told my wife we are gonna see exactly what the KR has in a couple of miles when it goes back to two lanes on the long hill climb up the next mountain. Sure enough as soon as we got there he jumped over in the right lane and hammered the oil burner rolling soot out the pipe. I of course gave it all she had to offer and while the KR and I gapped the Chevy by bus lengths, he was gapping me by inches. I couldn’t reel him in. I’ve driven my buddies Harley Davidson edition 6.0 with a Bully Dog programmer in extreme mode before, but I think this King Ranch had a lot more mods, especially exhaust. My wife and I did get a good laugh at the guy in the Silverado who brought the knife to the gun fight. We were loaded down with our usual luggage, food, 2 dogs, tools, a new love seat glider in a big box,and a hitch basket with a big cooler on it. I told her that dude in the Chevy just got his ass drug by Clark Grisswald in the “Family Truckster” !It blows away other vehicles that dare to try me.
Lol.... I was undefeated up until last weekend heading to my WV getaway cabin. My wife and I noticed two trucks up ahead running side by side trying to taunt each other behind traffic on a 2 lane. The one truck was a loud Ford King Ranch 6.0 Diesel with a monstrous pipe that was rolling coal every chance he got, and the other was a newer half ton Silverado. I snuck up and pulled the Chevy when traffic cleared and got between the two going back to single lane. I told my wife we are gonna see exactly what the KR has in a couple of miles when it goes back to two lanes on the long hill climb up the next mountain. Sure enough as soon as we got there he jumped over in the right lane and hammered the oil burner rolling soot out the pipe. I of course gave it all she had to offer and while the KR and I gapped the Chevy by bus lengths, he was gapping me by inches. I couldn’t reel him in. I’ve driven my buddies Harley Davidson edition 6.0 with a Bully Dog programmer in extreme mode before, but I think this King Ranch had a lot more mods, especially exhaust. My wife and I did get a good laugh at the guy in the Silverado who brought the knife to the gun fight. We were loaded down with our usual luggage, food, 2 dogs, tools, a new love seat glider in a big box,and a hitch basket with a big cooler on it. I told her that dude in the Chevy just got his ass drug by Clark Grisswald in the “Family Truckster” !

