Pre-ignition/knock at cold may be inevitable and "normal" for this engine

[Lil Red Broncette]

I like many others have observed quite a bit of pre-ignition until the engine gets up to temperature. My and other dealers says this is normal with this engine. I was thinking bad software algorithms, or something else should be able to "fix" this, but I just came across this video that pretty much explains why this is one of negatives about direct injection engines.

The video also explains some other down sides one of which is relevant to me as I don't take many longer trips with my one Bronco so it doesn't get up to temperature too often.

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[Tiresmoke410]

That guy and apparently mobile one engineers are assigning guilt to DI but it’s due to association.
DI is what allowed smaller turbo engines to exist. Smaller engines were a need to meet cafe. DI didnot cause the use of these style engines.
The reason DI allows this is because of its better fuel mixing and resistance to knock. With better mixing it reduces all the problems he associates with DI. Except dirty intake valves. That is a specific DI problem because there is no fuel to wash the intakes.
port injection has all the same other problems with cold start and blow by.
the reason it is now a problem is because of low tension rings to reduce friction and meet cafe. Blow by is worse now. It is not because DI is worse.
more cold knock is not because of DI. It is because to meet more restrictive cold start emissions the car is just leaner than it should be. It would be even worse with port injection assuming one could even get it to pass emissions.

 

[Duston@Lethal]

Higher octane will not only resist LSPI and knock, it will make more hp as the ecu adjusts for the higher octane.

In my opinion, almost every turbo motor nowadays should be sold as premium only or premium preferred.

 

[l88m22vette]

^ Agreed, I used 87 for the first thousand miles since I could, its cheaper, and was winter. I've been using 93 for the past month or two and its absolutely a better-driving, more powerful engine.

 

[Lil Red Broncette]

Higher octane will not only resist LSPI and knock, it will make more hp as the ecu adjusts for the higher octane.

In my opinion, almost every turbo motor nowadays should be sold as premium only or premium preferred.

Premium hasn't helped with the pre-ignition I experience at cold.

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