http://www.stratifiedauto.com/blog/low-speed-pre-ignition-in-the-mazdaspeed-disi-and-ford-ecoboost-motors/Bottom line, low RPM coupled with boost and a hot spot = big boom.
IMHO running a high quality oil coupled with the correct heat range plugs is the first defense and even more important since we are running typically at least 100 Ft/Lbs higher than stock.
The ecoboost has oil squirters under the pistons and a higher quality oil that can remove more heat will only help the situation. lower quality or degraded oil equals less protection.
Mixing E-85 also aids with cylinder cooling. Too much though can cause low pressure which can lead to wall wetting which can also lead to hot spots. this is why I believe running leaner keeping rail pressure high is something that might need to be explored and it is surely a balancing act.
I run ACES IV in my fuel as well for its effective octane boost but also because as it burns, it leaves a lubrication layer in the cylinder, again helping to combat any hot spot activity. I'm running a pretty hot tune and KR activity is low to zilch. Maybe its just luck but the 2015 has much less KR than the 2013 and the only difference on my end is the ACES, and I'm actually running a
lower blend of E.
There is a ton of info about this on the interwebz, feel free to add any research or discussion to this thread.
